@book{134800,
	author = {Johnson, David W., and Johnson, Roger T.},
	title = {Cooperative learning},
	publisher = {School of Education and Human Development, George Washington University},
	year = {1991.},
	series = {ASHE-ERIC Higher Education Reports},
	address = {Washington, DC},
	note = {"Prepared by ERIC, Clearinghouse on Higher Education, the George Washington University in cooperation with ASHE, Association for the study of Higher Education."}
}