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Citations and reference lists: for whom and for what purpose?

At the start of our scientific career, we may have entertained the idea of the scientific publication as a trustworthy report of facts critically discussed in a scientific context where personal interests were set aside. Today, more than ever, we enjoy rich sources of publication, but most of us have had to revise a somehow optimistic opinion for many reasons, the use of bibliography being one of them. The list of references is an indispensable part of a publication, putting the study, its results and the ensuing discussion into the appropriate context. Previous and related results are acknowledged, compared and discussed. The list serves the purpose of documentation, but is usually also a valuable link to further information – or is it? In a recent study, Simkin and Roychowdhury found that a seminal paper had been cited 4300 times with misprints in volume, page or year in 196 of the citations1. The most popular misprint occurred 78 times, suggesting an extensive use of ‘copy and paste’. One of the causes of the error was probably that the authors did not check the original publication. The same authors estimated that 20% of the citers actually read the original. It is tempting to end a bibliographical search at the reference list of a previous publication, or with the electronic version of the abstract. With increasing use of electronic sources the bibliography may improve on misprint, but probably not in erroneous interpretation of content. Another shortcut along the same lines would be referring to a review article. A review article can be quite appropriate at some point, but the number of review articles cited in some articles rather indicates that the authors were satisfied with too superficial a bibliographic search. A third common inconsistency is to leave out an appropriate reference. Can copied citations create renowned papers? That is the kind of question Simkin and Roychowdhury pose in a follow-up publication2. In a database of 24 000 papers, 44 papers were classified as renowned (cited more than 500 times). The habit of randomly picking references for further copying (pick three) in scientific publications lends itself to stochastic analysis. It turned out, not surprisingly, that such a multiplicative process generated 40 ‘renowned’ papers, purely by chance. The authors concluded: ‘In some spiritual sense, great scientists do exist. It is just that even if they would not exist, citation data would look the same’. However, referencing is not purely a matter of more or less correct scientific documentation. The authors’ personal preferences can sometimes be inferred from bibliographic lists: the philosophy might be make it an advertisement for your previous publications, add a reference to please your boss, your collaborating scientists or other allies, the journal’s editors or the anticipated reviewers. Chauvinism, personal sympathies and antipathies, competition, neglect, convention and availability are other factors reflected in the list3. Tactical citing can pay off: cite preferentially articles published in the journal where you submit your manuscript in the hope that the editors are favorably impressed. Small journals are desperately fighting for a place in the sun. One editor, in his letter accepting a manuscript for publication, requested that the authors include in their reference list at least one article previously published in the same journal. Another journal urged the authors to use recent publications in their bibliography, which, on one hand, animates the scientist to keep up with the literature, but on the other hand, does not encourage the use of original sources and pioneering studies performed some years earlier. Limitation of the number of references may impose difficult choices on the author. The introduction of impact factor has not been a blessing for the ethics of scientific publication. On the contrary, it adds pressure towards the skewness of citations. We have all become more tactical in our choices of where to publish and whom we cite. To