There is no distinction between print and ebooks. If the online source includes all the elements seen in the print version, such as date, publisher and place of publication, then the ebook should be referenced in the same way as the print version.
Please note that the edition should only be included if it is not the first edition, or a revised edition (as in the example below).
Speight, J.G. (2019) Global climate change demystified. 2nd edn. Chichester: Wiley.
Section E1 in CTR Harvard
CTR Harvard does not require illustrators of books to be listed except for comics (Section E20.11) We have adapted our guidance to include graphic novels and children’s books so that the illustrator’s work is fully acknowledged.
Lee, H. (2018) To kill a mockingbird. Adapter and illustrator F. Fordham. London: William Heinemann.
Children’s book (illustrated)
Breslin, T. (2012) An Illustrated treasury of Scottish folk and fairy tales. Illustrator Kate Leiper. Edinburgh: Floris.
CTR section E20.11 Comics
Venn, A. (2019) ‘Social justice and climate change’, in Letcher, T.M. (ed.) Managing global warming: an interface of technology and human issues. London: Academic Press, pp. 711-728.
Section E1.10 in CTR Harvard