Official ACS Citation Style Guide Manual:
The library supports two tools designed to help you keep track of and write citations. Below are the pros and cons of each tool.
NoodleBib: A step-by-step tool for creating and storing MLA, APA, and Chicago/Turabian styles.
Zotero: A tool for many citation styles. Ability to capture information quickly from web pages, online catalogs, webpages, etc.