How to write citations (references to other publications) in footnotes and endnotes, and how to format them, are questions that plague many authors. A science-minded friend in college recently put those questions to me in relation to a biology-focused blog he had just created. Wanting to give the best advice, I punted to my colleague and Springer-Verlag editor, Ronan Nugent.
Ronan's reply is below, with just minor edits for readability. He did provide some style guides along with his email, but those aren't important. What really grabbed my attention was his perspective. It's easy to agonize over just the right style to follow, and sometimes one should do that. Yet citation formatting is not passed to us from on high in stone tablets. The real world is messier than what you learned in English Composition.
Greetings from a remarkably mild Germany. I hope you're keeping well.
It seems that the "Springer Basic Style" is the preferred style for Springer's biology programs. Specifically, it seems to be close to the preferred style of the Council of Biology Editors (http://www.mhhe.com/mayfieldpub/tsw/doc-cbe.htm).
I've also added a recent version of the company's copyediting instructions. They are designed for freelance copyeditors and proofreaders rather than for authors, but there are some useful points in them. Perhaps you could look at Section 10 dealing with reference styles, and at Section 11 for specific notes about language and terminology style in biology. And you can see a variant of the APA style described in Section 10.3.6.
Please note that styles can be very specific within a particular subdiscipline. As an example, the American Society for Microbiology has its own style manual (mentioned at http://mbio.asm.org/site/misc/journal-ita_org.xhtml). Yet publishers may follow contrasting styles for publications (books, journals) even in the same field, for legacy reasons. So it might be a good idea for your friend to look up some of the publications of, say, his supervisors/lecturers or authors he knows in his field -- looking through books or journal articles online or in your library -- and try to work out what paradigms are standard in his specific area.
As a Springer editor, I think the key factors should be accuracy, completeness, and findability. Beyond those, an important original motivation behind imposing styles on references was to offer the reader something reasonably "clean" to view. Using a parallel presentation style aids quick scanning and comprehension.
The main motivation now is to enable linking between references. Springer is a member of CrossRef, and in the HTML versions of our online publications you can see buttons labeled "CrossRef", "PubMed", "PubMedCentral", "MATH" (Zentralblatt Math)", "MathSciNet", etc. These are links to the articles/papers/books that are listed in the citing article.
For these links into other publications to work, it's becoming increasingly important that there's nothing missing in the information required. The publishers' production units need to successfully pick up all the information presented. It's thus a good idea to fill all "fields", if you understand what I mean, e.g., adding issue numbers and page ranges in addition to volume numbers, including the publisher's name in the case of books, including the editors' names in the case of edited books, and so on.
All the above is the formal answer, assuming a formal publication such as a journal article or book. Your friend may think it's a little too much for a blog, even if what he intends is a list of formal references at the end of each entry.
Best regards, Ronan
Ronan packs a lot of perspective into a short email. He gives a glimpse of publishing reality that you may not be familiar with from your high-school and college English and writing courses.
The simple answer in my opinion is that if you're writing for a publisher, then do what the publisher asks. You'll just waste an over-stressed editors' time by arguing for anything else, and you'll have a short writing career too.
If writing for a blog, then you are the publisher and can set your own rules. Consistency is a hallmark of good writing, and Ronan's points about accuracy, completeness, and findability are spot on. At least be consistent within a single blog post, and even better is to be consistent across all posts that you make. Remember that findability is the ultimate goal. The whole point of a citation, after all, is to help readers find what is being cited.