Ahuja, B. N., author
Surjeet Publications , 1992
Buku Teks
C. Christhopher
Anmol Publicatioans PVT. ltd, 1997
Buku Teks
Ferguson, Donald L., author
National Textbook, 1994
Buku Teks
Passante, Christopher K., author
Prenada Media Group, 2008
Buku Teks
Christhopher, C.
Anmol Publicatioans PVT. Ltd, 1997
Buku Teks