Parker, R. A. C.
Weidenfeld and Nicolson, 1969
Buku Teks
Ryans, John K., author
Ohio Kent State University Press , 1974
Buku Teks
Parker, Earl R.
McGraw-Hil Book Company, 1967
Buku Teks
Parker, Earl R.
McGraw-Hill, 1967
Buku Teks
Davis, H. W. C.
Oxford University Press, 1960
Buku Teks