1
Cameron, Peter J. Introduction to algebra. 2nd ed. New York: : Oxford University Press 2008. http://ezproxy.library.qmul.ac.uk/login?url=http://www.vlebooks.com/vleweb/product/openreader?id=QMUL&isbn=9780191566226&uid=^u
2
Ledermann, Walter, Weir, Alan J. Introduction to group theory. 2nd ed. Harlow: : Longman 1996.