Gaya APA

Duffy, T, M., Kirkley, J, R. (2004). Learner-Centered Theory and Practice in Distance Education: Cases From Higher Education . New Jersey: Lawrence Erlbaum Associates.

Gaya MLA

Duffy, Thomas, M.., Kirkley, Jamie, R.. "Learner-Centered Theory and Practice in Distance Education: Cases From Higher Education". New Jersey: Lawrence Erlbaum Associates, 2004. Buku Tercetak.