E-Books
The reference list entry for an e-book includes the author, date, title, and source (URL or DOI). For a chapter in an e-book, include the chapter title and page numbers (if available).
Whole e-book:
Author, A. (date). Title of book. Retrieved from http://xxxxxxxxx
Author, A. (date). Title of book. doi:xxxxxxxxxxxx
Chapter in an e-book:
Author, A. (date). Title of chapter. In E. Editor (Ed.), Title of book (pp. xx–xx). Retrieved from http://xxxxxxxxx
Author, A. (date). Title of chapter. In E. Editor (Ed.), Title of book (pp. xx–xx). doi:xxxxxxxxxx
The in-text citation includes the author and date, as with any other APA Style citation.