Chaffe-Stengel, P., & Stengel, D. (2012). Working with sample data: Exploration and inference. https://doi.org/10.4128/9781606492147
What is a DOI?
Some library databases, such as Academic Search Ultimate and APA PsycInfo, list a Digital Object Identifier (DOI) for individual e-books. A DOI is a unique identifying number for an e-book. In the database record for an e-book, you will see an element that looks like this, which you should include at the end of your APA reference, preceded by "https://doi.org/":
This link will allow a reader to link to doi.org for more information about the e-book.
Miller, L. (2008). Careers for nature lovers & other outdoor types. Retrieved from http://www.ebscohost.com
No DOI? Use the URL for the database.
When a book has no DOI, write “Retrieved from” followed by the URL of the database. Use these URLs for library e-book databases:
Gladwell, M. (2008). Outliers: The story of success [Kindle DX version]. Retrieved from http://www.amazon.com
After the book title, put in brackets the name of the e-book reader, with the word “version.” Follow that with the DOI. If the book has no DOI, write “Retrieved from” followed by the URL of the site from which you downloaded the e-book.
Seton, E. T. (1911). The Arctic prairies: A canoe-journey of 2,000 miles in search of the caribou. Retrieved from http://www.gutenberg.org/etext/6818
Quina, K., & Kanarian, M. A. (1988). Continuing education. In P. Bronstein & K. Quina (Eds.), Teaching a psychology of people: Resources for gender and sociocultural awareness (pp. 200-208). Retrieved from http://www.ebscohost.com/academic/psycinfo
When using just a chapter from a book the same rules apply regarding DOI or no DOI as listed above, depending on where the book was retrieved.
See Style Guide, pp. 15-18.