ebrary, Inc, & Polanka, S. (2011). No shelf required: E-books in libraries. American Library Association.
Cita Chicago (17th ed.)ebrary, Inc, i Sue Polanka. No Shelf Required: E-books in Libraries. Chicago: American Library Association, 2011.
Cita MLA (9th ed.)ebrary, Inc, i Sue Polanka. No Shelf Required: E-books in Libraries. American Library Association, 2011.
Atenció: Aquestes cites poden no estar 100% correctes.