Common sense and ethics should determine your need for documenting sources. You do not need to give sources for familiar proverbs, well-known quotations or common knowledge. Remember, this is a rhetorical choice, based on audience. If you’re writing for an expert audience of a scholarly journal, for example, they’ll have different expectations of what constitutes common knowledge.
With more and more scholarly work being posted on the Internet, you may have to cite research you have completed in virtual environments. While many sources on the Internet should not be used for scholarly work (reference the OWL’s Evaluating Sources of Informationresource), some Web sources are perfectly acceptable for research. When creating in-text citations for electronic, film, or Internet sources, remember that your citation must reference the source in your Works Cited.
Sometimes writers are confused with how to craft parenthetical citations for electronic sources because of the absence of page numbers, but often, these sorts of entries do not require any sort of parenthetical citation at all. For electronic and Internet sources, follow the following guidelines:
Include in the text the first item that appears in the Work Cited entry that corresponds to the citation (e.g. author name, article name, website name, film name).
You do not need to give paragraph numbers or page numbers based on your Web browser’s print preview function.
Unless you must list the Web site name in the signal phrase in order to get the reader to the appropriate entry, do not include URLs in-text. Only provide partial URLs such as when the name of the site includes, for example, a domain name, like CNN.com orForbes.com as opposed to writing out http://www.cnn.com or http://www.forbes.com.