Williams, Bill
John Wiley & Sons, 1978
Buku Teks
Cochran, William G.
John Wiley , 1963
Buku Teks
Raj, Des
McGraw-Hill, 1968
Buku Teks
Scheaffer, Richard L.
Brooks/Cole Cengage Learning, 2012
Buku Teks
Cochran, William G.
John Wiley & Sons, 1953
Buku Teks SO