Anything relating or conforming to the
style guidelines put forth in
Kate Turabian's
A Manual for Writers of Term Papers, Theses, and Dissertations, which is alternately referred to as the Turabian Manual and the
Chicago Manual. The manual covers everything from
comma placement to
abbreviations, but is most famous for its sections on
footnote citations and
bibliographic references, which exhaustively
proscribes ways of citing pretty much every possible form of
source, including in more recent editions developments such as
online sources.
"Turabian style"/"Chicago style" references are standard for works by historians, and mandatory in many academic history courses. For examples of this kind of style, go on any search engine and state for "Turabian" and you will find pages of sample Turabian references. Of course, almost every library in the universe has a copy of the Turabian guide, so checking the original book is easy.