Whitelaw, Thomas A.
Blackie Academic & Professional, 1995
Buku Teks SO
Barnes, Wilfred E.
D. C. Hearth, 1963
Buku Teks SO
Ehrlich, Gertrude
PWS-Kentt Publishing, 1991
Buku Teks SO
Pinter, Charles C.
McGraw-Hill, 1982
Buku Teks SO
Fraleigh, John B.
Addison-Wesley Publishing Co., 1994
Buku Teks SO