Cuff, E.C.
Routledge, 1995
Buku Teks
edited by E.C. Cuff; G.C.F. Payne
George Allen and Unwin, 1984
Buku Teks SO
Sherman, Howard J.
Harper & Row, 1979
Buku Teks
Brym, Robert J.
Wadsworth and Cengage Learning, 2013
Buku Teks
Ross, H. Laurence (Hugh Laurence)
McGraw-Hill, 1963
Buku Teks