Snedecor, George W., author
The Iowa State University Press, 1982
Buku Teks
Taylor, John Keenan
Lewis Publishers, 1990
Buku Teks
Sigel, Andrew F., author
John Wiley & Sons, 1996
Buku Teks
Keeping, E.S., author
Van Nostrand Reinhold, 1962
Buku Teks
Dobson, Annette, author
Chapman and Hall, 1983
Buku Teks