For eBooks use the same principles as print books with URL replacing publisher details.
Surname, A. B. (year). Title: Subtitle. Retrieved from URL
For items with a Digital Object Identifier (DOI), this replaces the URL.
Surname, A. B. (year). Title: Subtitle. doi:xxxxxxxxxxxxxxx
Clark. J. (2008). Aborigines & activism: Race, Aborigines & the coming of the sixties to Australia. Retrieved from http://search.informit.org/
Note: Only one piece of source information is required per reference (e.g. publication details or retrieval URL). Using a retrieval URL clearly indicates the source is an ebook. No retrieval date required.
Clark (2008) asserts that the sixties were a turbulent time ...