CHANDRUPATLA, Tirupathi R. and BELEGUNDU, Ashok D (2002) UNSPECIFIED Prentice Hall, New Jersey. ISBN 978 013 041 591 9

DHILLON, B.S. (2002) UNSPECIFIED CRC Press, Boca Raton. ISBN 978 158 716 142 7

KAHNDAN, N. Nirmala (2002) UNSPECIFIED CRC Press, Boca Raton. ISBN 978 156 676 995 7