1Hmoudova D E.MOOCs motivation and communication in the cyber learning environment[J].Procedia-Social and Behavioral Sciences,2014,131(5):29-34.
2Kim M K,Kim M S,Khera O,et al.The experience of three fl ipped classrooms in an urban university:an exploration of design principles[J].The Internet and Higher Education,2014,22(7):37-50.