Stark, Rodney. Sociology 10th. thomas wadsworth. 2007. ISBN 978-0-495-09344-2.Lenski, Gerhard E. Power and Privilege: A Theory of Social Stratificaion. McGraw-Hill. 1966. ISBN 978-0-07-037165-1.Collins, Randall. Four Sociological Traditions: Selected Readings. Oxford University Press. 1994. ISBN 978-0-19-508702-4.Thio, Alex. Sociology: A Brief Introduction 7th. Pearson. 2008. ISBN 978-0-205-40785-9.