Many disciplines have their own citation styles, such as the American Sociological Association and the American Chemical Society. You can find links to each of these styles below.
ACS is the citation style used by the American Chemical Society.
The ACS Style Guide: A Manual for Authors and Editors (2006)
MHSL Reference Collection QD 8.5 A25 2006
ACS Publications Reference Style Guidelines from the American Chemical Society.
AIP is the citation style for the American Institute of Physics.
AIP Style Manual (4th edition) from MIT
Preparing your Manuscript form AIP Publishing
ALWD is the Association of Legal Writing Directors.
Introduction to Basic Legal Citation (2014 ed) from Cornell University Law School.
AMS is the style of the American Mathematical Society.
Author Packages for Publishing with the AMS from the American Mathematical Society.
AMS Author Handbook from the American Mathematical Society.
AP is the style manual for the Associated Press. It is used by those in the media.
Associated Press Stylebook and Briefing on Media Law
MHSL Reference Collection PN 4783 A83 2007
Associated Press Style from the Purdue Online Writing Lab.
APSA is the style for the American Political Science Association.
ASA is the format for the American Sociological Association.
ASA Style from the Purdue Online Writing Lab
Quick Tips for ASA Style from the American Sociological Association
ASCE is the American Society of Civil Engineers.
Publishing in ASCE Journals: A Guide for Authors
Publishing Proceedings with ASCE: A Guide for Editors and Conference Committees
ASME is the American Society of Mechanical Engineers.
The Bluebook is used for legal citations.
The Bluebook: A Uniform System of Citation (18th ed)
MHSL Reference Collection KF 245 U5
Introduction to Basic Legal Citation (2014) from Cornell University Law School
Bluebook Guide from Georgetown Law Library
CSE is the Council of Science Editors.
Council of Science Editors (CSE) (Citation/Sequence System) from Colorado State University.
CSE Scientific Style and Format Citation Guide from Penn State University Libraries.
Government publications have their own citation style.
The Complete Guide to Citing Government Information Resources: A Manual for Social Science & Business Research (3rd ed):
MHSL Reference Collection J 9.5 G37 2002
Citing Government and Legal Materials from UAB Mervyn H. Sterne Library
Citing Government Sources from Georgetown University Library
IEEE is the Institute of Electrical and Electronics Engineers.
NLM is for the National Library of Medicine
Citing Medicine: The NLM Style Guide for Authors, Editors, and Publishers