I know that there are many styles to write citations and footnotes and that they are all equally good (as long as the reference is complete), but I would like to know if mathematicians follow some particular guidelines.
If so, can you add a link (or a reference) to a good handbook covering the details of "the mathematicians' manual of style"?


This website, by Dr. Michael K. Kinyon (Wayback Machine), has many resources which will answer your question; however, I no know of any MLA for math.
Math Write (Wayback Machine) A huge collection of Books, Articles available for download or viewing, and Websites: about how to write mathematics.
Because this is not my own work, I suggest that if Dr. Kinyon is a user here, give him the bounty.