APA
Garrison D. R., . (2019). E-learning in the 21st century : a community of inquiry framework for research and practice 3rd ed. Routledge: London.
Chicago
Garrison D Randy, . 2019. E-learning in the 21st century : a community of inquiry framework for research and practice 3rd ed. Routledge: London.
Harvard
Garrison D. R., . (2019). E-learning in the 21st century : a community of inquiry framework for research and practice 3rd ed. Routledge: London.
MLA
Garrison D Randy, . E-learning in the 21st century : a community of inquiry framework for research and practice 3rd ed. Routledge: London. 2019.