Citation patterns are also known to be affected by unethical behavior of both the authors and journal staff. Such behavior is called impact factor boosting, and was reported to involve even the top-tier journals. Specifically the high-ranking journals of medical science, including the Lancet, JAMA and New England Journal of Medicine, are thought to be associated with such behavior, with up to 30% of citations to these journals being generated by commissioned opinion articles.  On the other hand, the phenomenon of citation cartels is rising. Citation cartels are defined as groups of authors that cite each other disproportionately more than they do other groups of authors who work on the same subject. 
Citing sources at the end – A simple solution to the problem above: put the sources at the end! Unfortunately, the conclusion sounds like this: “And, in conclusion, I got my sources from…” followed by a list of vague sources. Why is this bad? Well, the conclusion is supposed to summarize the relevant information and assess the purpose of the speech, perhaps even urge us to action or provide the next steps. This one sounds like a reference page. That just doesn’t work. In addition, we have no idea which facts, figures, and quotes go to which sources (and if you only have one source, you better do some more research!).