Croxton, Frederick E., author
Prentice-Hal, 1967
Buku Teks
Sellers, Gene R.
WB. Saunders, 1977
Buku Teks
Snedecor, George W., author
The Iowa State University Press, 1964
Buku Teks
Stahl, Sidney M., author
Mosby, 1980
Buku Teks
Gordon, Sheldon P., author
McGraw-Hill, 1994
Buku Teks