Scheaffer, Richard L., author
Brooks/Cole Cengage Learning, 2012
Buku Teks
Raj, Des, author
McGraw-Hill, 1968
Buku Teks
Williams, Bill
John Wiley & Sons, 1978
Buku Teks
Thompson, Steven K.
John Wiley & Sons, 1992
Buku Teks
Scheaffer, Richard L., author
Duxbury , 1990 Press
Buku Teks