We recently received a question on ref-ref about citing works read on a Kindle, and found several sources which might help.
The 16th edition of the Chicago Manual of Style
14.166Books downloaded from a library or bookseller
The majority of electronically published books offered for download from a library or bookseller will have a printed counterpart. Because of the potential for differences, however, authors must indicate that they have consulted a format other than print. This indication should be the last part of a full citation that follows the recommendations for citing printed books as detailed throughout this section. See also 14.4–13.
Austen, Jane. Pride and Prejudice. New York: Penguin Classics, 2007. Kindle edition….
Note that electronic formats do not always carry stable page numbers (e.g., pagination may depend on text size), a factor that potentially limits their suitability as sources. In lieu of a page number, include an indication of chapter or section or other locator. See also 14.17.
The style manual also has a Q&A section, which includes this:
1. Jane Austen, Pride and Prejudice (New York: Penguin Classics, 2008), Microsoft Reader e-book, chap. 23.
Q. Are there any conventions yet for citing a text on Kindle? That is, because the type size is variable, there are no page numbers in a Kindle edition; instead, there is a running locator at the bottom of each screen. I’m wondering whether it would be permissible to cite these location numbers rather than look up my quotes in a hard copy of the text.
A. Yes, you can cite the location numbers, although unless a reader has the Kindle edition of that work, the numbers will be of little use for finding the text. Like unpaged online content, Kindle editions are best cited with reference to chapter titles or numbers, subheadings, or a unique phrase that can be located by searching.
The APA style blog has a discussion of this too. Here is the original entry.
How Do I Cite a Kindle?
E-book readers, like the popular Kindle from Amazon.com, are revolutionizing the way we interact with the printed page. Although most e-book content has leaned toward the nonscholarly, major textbook manufacturers are now partnering with Amazon to produce e-textbooks, with a pilot program to be run at six universities in Fall 2009. They have recently debuted the Kindle DX ($489 retail), which in comparison to the original Kindle boasts a bigger screen (9.7” vs. 6” diagonally) and native support for PDFs, both key to good textbook reproduction.
For the students and scholars who use Kindles (or other e-book readers) when writing papers, the next question becomes, how do I cite material I read on a Kindle?
For the reference list entry, you’ll need to include the type of e-book version you read (two examples are the Kindle DX version and the Adobe Digital Editions version). In lieu of publisher information, include the book’s DOI or where you downloaded the e-book from (if there is no DOI). For example:
Gladwell, M. (2008). Outliers: The story of success [Kindle DX version]. Retrieved from Amazon.com
Brill, P. (2004). The winner’s way [Adobe Digital Editions version]. doi:10.1036/007142363X
Consult Chapter 7 of the 6th ed. of the Publication Manual (examples 19, 20, and 21) for some more help. If the full URL is very long (the one for Gladwell’s book was), you may give instead the homepage URL with a description of where to go from there, or the store name—your preference (e.g., Amazon Kindle store or http://www.amazon.com).
In the text, however, citation can get confusing because e-books often lack page numbers (though PDF versions may have them). Kindle books have “location numbers,” which are static, but those are useless to anyone who doesn’t have a Kindle too. To cite in text, either (a) paraphrase, thus avoiding the problem (e.g., "Gladwell, 2008"), or (b) utilize APA’s guidelines for direct quotations of online material without pagination (see Section 6.05 of the manual). Name the major sections (chapter, section, and paragraph number; abbreviate if titles are long), like you would do if you were citing the Bible or Shakespeare.
Gladwell’s book has numbered chapters, and he’s numbered the sections in the chapters. An example direct quotation might be this:
One of the author’s main points is that “people don’t rise from nothing” (Gladwell, 2008, Chapter 1, Section 2, para. 5).
The comments also have some useful points.
This may be soon be easier, because, according to Amazon, there will soon be a free update for Kindle which will have
• Real Page Numbers – Our customers have told us they want real page numbers that match the page numbers in print books so they can easily reference and cite passages, and read alongside others in a book club or class. Rather than add page numbers that don’t correspond to print books, which is how page numbers have been added to e-books in the past, we’re adding real page numbers that correspond directly to a book’s print edition. We’ve already added real page numbers to tens of thousands of Kindle books, including the top 100 bestselling books in the Kindle Store that have matching print editions and thousands more of the most popular books. Page numbers will also be available on our free “Buy Once, Read Everywhere” Kindle apps in the coming months. As with all of Kindle’s features, we want you to lose yourself in the author’s words, so Page Numbers are only displayed when you press the Menu button.