APA Style

Garrison, D, R. (2017). E-learning in the 21st century: a community of inquiry framework for research and practice (Ed. 3.). New York: Routledge.

MLA Style

Garrison, D, Randy. "E-learning in the 21st century: a community of inquiry framework for research and practice". Ed. 3. New York: Routledge, 2017. Text.