The same basic rules apply for e-books as they do for print books with a few additions.
• Add the [Online] to indicate format
• Include the source of the e-book which is often different than the publisher e.g. Available: Safari e-book.
Standard format for citation
[#] A. Author, Title of E-book. Place: Publisher, Date of original publication. [Format]. Available: Source.
 J. W. Matiko and S. Beeby. Applications of Energy Harvesting Technologies in Buildings. Norwood, MA: Artech House, 2017. [Online]. Available: EBSCO e-book.
Chapter from an electronic book
 V. Carrara and H.K. Kuga, "Current and Speed Control Operating Modes of a Reaction Wheel," in Dynamics and Control of Technical Systems, J. M. Balthazar, P. B. Gonçalves, S. Kaczmarczyk, A. Fenili, M. Silveira and I. Herrera Navarro, Eds. Pfaffikon, Switzerland: Trans Tech Publications, 2015, pp. 170-180. [Online]. Available: EBSCO e-book.
Article entry from an electronic reference book - with an author
 D. Ince, "Acoustic coupler," in A Dictionary of the Internet. Oxford: Oxford University Press, 2001. [Online]. Available: Oxford Reference Online.
Article entry from an electronic reference book - without an author
 "Acoustic coupler," in A Dictionary of Computing, 6th ed., S. M. H. Collin, Ed. London, UK: Bloomsbury, 2010. [Online]. Available: Oxford Reference Online.