Shepherd, John, author
Pitman, 1993
Buku Teks
Gray, Alexander, author
McGraw-Hill , 1962
Buku Teks
Shepherd, John, author
Pitman, 1973
Buku Teks
Bhatia, S. L., author
Khanna Publishers, 1976
Buku Referensi
Clayton, Albert E., author
Longmans, 1966
Buku Teks