Raychoudhary, S.C.
Surjeet Publications, 1984
Buku Teks
Caenegem, R. C. van, author
North-Holland Publishing, 1978
Buku Teks
Jackson, William Thomas Hobdell
Collier, 1966
Buku Teks
compiled and edited by William L. Langer
Houghton Mifflin, 1968
Buku Referensi
Timings, R.L. (Roger Leslie), 1927-, author
Longman, 1991
Buku Teks