Citations for online articles and books need a few more pieces of information than citations to the print versions do.

• Check the styles on this guide to find the requirements for citing ebooks, online articles, and other online items
• Citations for online items usually (but not always) require a URL/DOI and the date you accessed it
• No citation tool is perfect -- always check your bibliography to make sure that each citation includes every piece of information that it needs to be complete and correct