A digital object identifier (DOI) is a unique number/code to identify content and provide a reliable link to its location on the Internet. Unlike a URL, a DOI never changes.
Author, A. (Date of publication). Title of book in italics: Subtitle. Retrieval information
Example—reference list entry
Borras, I. (2016). Adult learning for self and relational growth (ALG): An integrative developmental model. https://doi.org/10.1007/978-94-6300-417-6
Example—in-text citation
Borras (2016) notes … (p. 65).
or
(Borras, 2016, p. 65).