The library provides full ebook access to the most recent edition of The Chicago Manual of Style [CMOS], the style frequently employed by historians--and art historians. In addition to providing structure for how one should cite, CMOS offers guidance in giving credit and seeking permission, when to paraphrase rather than quote, and how to indicate alterations in direct quotes. 

While Zotero is a great way to collect, organize, and eventually cite sources, referring to CMOS is often needed for tricky sources and formatting/stylistic issues.