Primary Sources and Citing References

(By Dr. McShaffrey)

 We make a big deal out of insisting on proper reference citation and the use of primary sources. Since scientific writing differs from the experiences you may have had in English classes; let me clarify these two points.

Every idea you get from another source must acknowledge that source in the text where the idea is stated. This is known as citation, and failure to do so is plagiarism. The general rule is that any information that is not general knowledge (that is, anything you found in an article, book etc.) must have the reference cited. For instance, the fact that a mayfly is an insect is general knowledge, the fact that the mayfly Stenacron interpunctatum prefers slow currents is not, and must be cited. If you do original experiments or make original observations, you do not need to cite these, but you must also include a methods section so that others may try to reproduce your results. Note that original conclusions that you draw based on information presented need not be cited. For instance, if Jones reported in 1985 that a species of ant is dependent on a certain plant, and Smith reported in 1986 that the plant is going extinct, then you could conclude that the ant is also going extinct - but even here you would have to cite Jones and Smith as evidence for your conclusion. Similarly, if Thompson says that there are 315 species of bees in Borneo, and you write "there are over 300 species of bees in Borneo", or "there's bunches of bees in Borneo", you must acknowledge Thompson, even though you didn't quote her exactly. If you hadn't gotten the idea from her, you wouldn't have had a clue as to how many bees there were (short of counting them, then your paper would be a primary source). If in doubt - cite the source!

Consider the following paragraph from a paper I wrote:

"Little ecological information on E. needhami has been published. Ecological studies concerning the diet of organisms may give clues to the function of their mouthparts. According to Cummins et al. (1984, 315) the Ephemerella belong to the collector- gatherer and scraper functional feeding groups (FFGs). Hawkins (1985, 412) described a western species, E. infrequens, as a diatom scraper, detritus shredder, and collector-gatherer. Sweeney & Vannote (1981, 200) studied 6 species of ephemerellids, 2 of which belong to the genus Ephemerella; all of the ephemerellids in their study fed on diatoms and detritus. Other Ephemeridae have usually been considered to be collector-gatherers (Cummins et al., 1984, 315)."

The first sentence has no citations; it is a fact derived from my study of the literature. The next sentence is transitional and introduces no new information, just an obvious truism. The remaining sentences summarize the results of other worker's studies, and I gave them each credit for what they discovered. Note that each citation is accomplished by stating the author(s) name(s) and the date of the paper in such a way that it is clearly associated with the idea being discussed. Often, the name is part of the sentence, and only the date is enclosed in parentheses; however, it is also proper simply to put both the name and the date in parentheses, as is done in the last sentence. The abbreviation "et al." is used when more than two authors wrote a paper.

This form of citation is very common (but not universal), and we want you to use it. Read through several articles in The Ohio Journal of Science to get a feel for the general style of scientific writing, as well as how to handle references.  At Marietta College, we make one important change to the way references are cited in the text.  We ask you to include the page number  where the relevant information is found.  This allows your instructor to check and ensure that you are getting the right information and putting it into your own words (when not quoting directly, see below).  Unless otherwise instructed, you should include page numbers with all your citations.

The next most common mistake I encounter (after failing to cite a reference at all) is what I call "lumping". This occurs when all of the information you use in a paragraph comes from the same source, and you try to reference that source simply by putting it at the end of the paragraph. That is not acceptable. You must acknowledge a source within the sentence (or clause) in which you use it. If that means that each sentence in your paragraph ends with (Brown, 1986, 35), so be it. If that monotony bothers you (and it should), you can avoid it by finding more sources to cite, or citing the one source in different ways: Brown (1986, 35), according to Brown (1986, 35), Brown (1986, 35) also found, and so on.

A note on quotes: In the humanities, frequently the exact wording of the ideas of the author under consideration is critical to the reader's understanding of the points being made in the paper. In this context, it is necessary to use exact quotes (with citations!). In the sciences, we are supposed to be "objective". This means writing methods sections in the passive voice to avoid the use of the pronoun "I", which distracts the reader from the work that was done and focuses attention on the scientist who performed it. Quotes also take emphasis away from the results and put emphasis on personalities. Unless the exact wording of the author you are citing is critical to the concept you are reviewing, paraphrase the author(s) and cite appropriately. Note that changing one or two words is not enough to paraphrase correctly - it must be a substantial revision, or again, you will be guilty of plagiarism. One way to avoid inadvertently quoting an author exactly is to paraphrase as you make notes, and then paraphrase your notes as you write your paper.

At the end of the paper, you must have a section listing all the papers you have cited. Again, follow the format in the Ohio Journal of Science or consult the . Do yourself a favor, and find an article now (preferably one dealing with your topic), and photocopy it, so that you can use it as a guide to solving different style problems. Note that journal articles are handled differently than books in the Literature Cited section. Pay attention to where the periods and commas go, but don't get too paranoid about these - be consistent.


Reference Formats

      Citations point to 'references' listed in the "Literature Citations" section of the lab report, where the sources of the information are listed alphabetically.  Again, the specific format for references varies among disciplines, however, use the following formats for your lab reports: 

Reference from a book:

McKinney M, Schoch R. 1998. Environmental science: systems and solutions. Sudbury (MA): Jones and Bartlett Publishers; 988p.

 Chapter of an edited book:

Crabbé J, Barnola P.  1996.  A new conceptual approach to bud dormancy on woody plants.  
In: Lang G, editor.  Plant dormancy. Wallingford, Oxon (GB): CAB International; p. 83-113.

Marietta College Biology Department. 2003. Observation, ethograms and wall-seeking behavior.
In: Introductory biology lab I manual.  Marietta (OH): Marietta College; p. 1-19.

 From a journal (1o and 2o sources):

Smith AB, Jones CD, Banks EF. 1994. Effects of absenteeism on student grades in biology.  American Journal of Biology Class Attendance. 123(4): 19-23.

From an ONLINE ONLY Journal:

Muscedere ML, Traniello JFA. 2012. Division of labor in the hyperdiverse ant genus Pheidole is associated with distinct subcaste- and age-related patterns of worker brain organization.
PLoS ONE 7(2): e31618. doi:10.1371/journal.pone.0031618.

 From a magazine (3o source) which does not use volume numbers (most DO):

Beckridge N. 1997. The parasitic wasp’s secret weapon. Scientific American; November, 82- 85.

[Note that for tertiary sources, sometimes the month of publication substitutes for the journal volume number ]

From state or federal documents:

Ohio EPA ( Ohio Environmental Protection Agency).  1988.  Biological criteria for the protection of aquatic life.  Volume II, user’s manual for biological field assessments of Ohio surface waters.  
Columbus (OH): Ohio EPA; 135p.

Smith RD , Ammann A, Bartoldus C, Brinson MM.  1995.  An approach for assessing wetland functions using hydrogeomorphic classification, reference wetlands and functional indices.  
            Wetlands Research Program Technical Report WRP-DE-9.  Vicksburg (MS):  US Army Corps of Engineers Waterways Experiment Station; 88p.

USDHHS (US Department of Health and Human Services), Center for Disease Control and Prevention.  1993.  Fluoridation census, 1992.  Atlanta (GA): CDC; 686p.

References to web pages (only allowed for special assignments)

 For some assignments you may be asked to search for information on the internet.  A reference for such information must include, as a minimum, this information in following order:

  1. Author of the web page or ‘anonymous’ if author is not identified.

  2. Title of the web page from which the information was obtained.  Follow title with [Internet].

  3. Name of organization that prepared the web page, and, when present, the name of the company, government agency, or university that sponsors that organization. Sometimes this can only be found by inspecting the URL.

  4. Date of page creation or last update: date cited [in brackets] i.e. [created 2008 May 15; cited 2008 Sep 14].  Sometimes this can be obtained directly from the page or through the ‘View, Page Source’ option on the pull-down menu.

  5. URL (in parentheses) of the page.

 URL, title and other information can be copied from browser to your document using the ‘cut’ and ‘paste’ functions.


Franchesca P, Kjeldsen K, Hughey K.  Algae: the forgotten treasure of tidepools. [Internet] Department of Biology at Sonoma State.  [modified 1997 May 23; cited 1998 Oct 5] (  

Matthews HS, Lave LB.  Price setting for green design. [Internet]  The Green Initiative.  Carnegie Mellon University.  [no date given:  cited 2008 Jun 18] (  

Anonymous. Algal bioassays (nutrient testing). [Internet]  Bureau of Laboratories, Florida Department of Environmental Protection.  [modified 2005 Feb 1; cited 2007 Aug 9]   (

These figures might help explain how to format the most common types of references you will be using:

From an ONLINE ONLY Journal (if the journal appears in print but you access it online, use the format ABOVE and cite it as if you were looking at the print version). If the journal is online only, use the format BELOW:


Below are a number of citations given as an example.  Remember that you can use web pages only in RARE circumstances.


Alexander RD.   1974.  The evolution of social behavior.  Annual Review of Ecology and Systematics 5:  325-383.

Anonymous. Money facts: fun facts [Internet].  Bureau of Engraving and Printing; The United States Treasury.  [cited 2003 Dec 20]

Breder CM Jr.  1967.  On the survival value of fish schools.  Zoologica 52(4):  25-40.

Brooks R, Yasukawa K. Laboratory exercises in animal behavior - ethograms of mice. [Internet] Animal Behavior Society. 
        [modified 2000 Jul 20; cited 2004 Jun 5]. (

Brubaker L. 1975. Wall-seeking behavior in mice. In: Price EO, Stokes AW, editors. 
        Animal behavior in laboratory and field. New York (NY): W.H. Freeman and Company; p. 39-41.

Darwin C. 1966. On the origin of species. (A facsimile of the first edition with an introduction by Ernst Mayr. 2nd Printing). Cambridge (MA): Harvard University Press.

Dewsbury D. 1978. Comparative animal behavior. New York (NY): McGraw-Hill Book Company; p. 3-7.

Griffiths SW, Magurran AE.  1997.  Familiarity in schooling fish: How long does it take to acquire? 
      Animal Behaviour 53(5):  945-949.

Griffiths SW, Magurran AE.  1999.  Schooling decisions in guppies (Poecilia reticulata) are based on 
familiarity rather than kin recognition by phenotype matching.  Behavioral Ecology and  Sociobiology 
            45(6):  437-443. 

Houck L, Drickamer LC. 1996. Introduction. In: Houck LD, Drikamer LC editors. Foundations of animal 
        behavior: classic papers with commentaries. Chicago (IL): The University of Chicago Press; p. 1-3.

Keenleyside MHA.  1955.  Some aspects of the schooling behaviour of fish.  Behaviour 8:  183-247.

Keenleyside MHA.  1975.  Schooling behavior in fish.  In:  Price EO, Stokes AW, editors.  
        Animal  behavior in laboratory and field, 2nd ed. New York (NY): W.H. 
        Freeman and Company; p. 101-104.

Levine J, Miller K. 1994. Biology: discovering life, 2nd ed. Lexington (MA): 
        D.C. Heath and Company; pp. 682-686 & Ch. 46.

Lewis R, Parker B, Gaffin D, Hoefnagels M. 2007. Life, 6th ed. Boston (MA): McGraw Hill; 1012p.

Maier R.  1998.  Comparative animal behavior: an evolutionary and ecological approach. 
(MA):  Allyn and Bacon; p. 327-328 & 335-336.

Moerman D. Native American ethnobotany database [Internet].  Department of Anthropology at The
of Michigan Dearborn .  [modified 2003 May 03; cited 2003 Dec 20] (

Niwa H-S.  1994.  Self-organizing dynamic model of fish schooling.  Journal of Theoretical Biology 
      171(2): 123-136.

 Niwa H-S.  1996.  Newtonian dynamical approach to fish schooling.  Journal of Theoretical Biology 
      181(1): 47-63.

Niwa H-S.  1998.   School size statistics of fish.  Journal of Theoretical Biology 195(3): 351-361.  

Peuhkuri N.  1997.  Size-assortative shoaling in fish: The effect of oddity on foraging behaviour. 
Animal Behaviour 54(2): 271-278.  

Peuhkuri N, Ranta E, Seppa P.  1997.  Size-assortative schooling in free-ranging sticklebacks.
           Ethology 103(4): 318-324.

Simpson B, Ogorzaly M.  1986.  Economic botany: plants in our world. New York (NY): McGraw-Hill. 

For more information on citations see this web page:

or consult the sample lab report at:

 If you cannot find an example of how to handle a particular reference, consult a RECENT edition of the Ohio Journal of Science, or the CSE manual:

Council of Science Editors, Style Manual Committee.  2006.  Scientific style and format: the CSE manual for 
     authors, editors, and publishers, 7th ed.  Reston (VA): The Council; 658p.

 The CSE manual is in the reference section of the library; we are using the N-Y system mentioned in the manual.

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