A variety of content is available from this platform. But in most cases, the content is usually derived from a book. You would therefore follow the style conventions for a book or book chapter.
For example, under the Quick Reference Tab, if you choose Diagnostic Tests,
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You will see the ebook , Pocket Guide to Diagnostic Tests, 6e.
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Another example of an ebook are the Case Files. If you read the copyright statement for each case, this material is classified as a digital book. Each case is therefore like a chapter in a book.
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When the content is not derived from ebook, you probably will cite as a website, image, or video. Questions? Please contact the library.