Johnstone, Sydney J. (Sydney James), author
John Wiley & Sons, 1961
Buku Teks
Hanley, N. author
CBS Publishers & Distributors Pvt Ltd, 2016
Buku Teks
Buku Teks
Wang, K.P.
Westview Press, 1977
Buku Teks
Austin, George T., author
McGraw-Hill, c1986
Buku Teks