Neckers, Douglas C.
John Wiley & Sons, 1977
Buku Teks
McMurry, John
Brooks/Cole, 2007
Buku Teks
Boxer, Robert J.
McGraw-Hill, 1998
Buku Referensi
Solomons, T.W. Graham
John Wliley & Sons , 2011
Buku Teks
Morrison, Robert Thornton
Prentice-Hall, 1992
Buku Teks