Yearsley, R.B., author
Gower Press, 1974
Buku Referensi
White, Martin, author
Facet Publishing, 2005
Buku Teks
White, Martin, author
Facet Publishing, 2005
Buku Teks
Lasser, J.K. (Jacob Kay), author
McGraw-Hill, 1960
Buku Teks
Goyal, R.C., author
Prenctice Hall of India, 1998
Buku Teks