Williams, M. L., & Covington, B. (1999). Distance learning: The essential guide. Thousand Oaks, Calif: Sage.
Chicago Style CitationWilliams, Marcia L., i Barbara Covington. Distance Learning: The Essential Guide. Thousand Oaks, Calif: Sage, 1999.
Cita MLAWilliams, Marcia L., i Barbara Covington. Distance Learning: The Essential Guide. Thousand Oaks, Calif: Sage, 1999.
Atenció: Aquestes cites poden no estar 100% correctes.