Roberts, John D.
W.A. Benjamin , 1977
Buku Teks
Mee, A.J.
J.M. Dent and Sond , 1960
Buku Teks
Kice, John L.
Macmillan Publishing Company, 1974
Buku Teks
Beyer, Hans, author
[Publisher not identified], [Date of publication not identified]
Buku Teks
Solomons, T. W. Graham, author
John Wiley & Sons, 1992
Buku Teks