You’re writing a book. You’re using other materials as sources. But have you considered your right to use the material? Book publishing is a whole different world from those days of school research papers, when you could quote away and just throw a bibliography at the end. There are many myths out there about using material from another source in your own work:
“If I cite the source of the material then it’s okay to use it.”
“If I use 200 words or less it’s okay to use it without getting permission.”
“I’ll just paraphrase the text from the other source whenever I use it.”
You may have heard writers say they can use content without permission because of something called “fair use.” The distinction between fair use of another’s content and infringement is not easily defined. Determination of whether or not a use falls under “fair use” is based on several factors, including: the purpose and character of the use (for-profit or educational use); the nature of the copyrighted work; the amount used in relation to the copyrighted work as a whole; and the effect of that use on the potential market for, or value of, the copyrighted work.[i]
Illustrations, tables, text, and music created by others are the most common materials that require permission. Paraphrasing copyrighted content does not exclude you from being in violation. The Chicago Manual of Style, the style manual most commonly used in book publishing, refers to extensively paraphrased work being treated as “disguised copying.”
Always double-check material you are quoting for accuracy. Limit the use of others’ content, and get permission whenever possible. Always cite any information that is not from your own source of knowledge, but remember that simply citing does not protect you from violating copyright. Consult your editor and publishing support provider. When in doubt, contact the source of the information you want to use and ask for permission. That extra step can mean avoiding thousands of dollars in fines, or even jail time, if you’re found to have willfully committed copyright infringement.
[i] Source: The Chicago Manual of Style Online, http://www.chicagomanualofstyle.org/.