you can use this format: Author. Title. Title of container (self contained if book), Other contributors (translators or editors), Version (edition), Number (vol. and/or no.), Publisher, Publication Date, Location (pages, paragraphs and/or URL, DOI or permalink). 2nd container’s title, Other contributors, Version, Number, Publisher, Publication date, Location, Date of Access (if applicable).
example: The Purdue OWL Family of Sites. The Writing Lab and OWL at Purdue and Purdue U, 2008, owl.english.purdue.edu/owl. Accessed 23 Apr. 2008.