Kay, Ronald D.
McGraw-Hill, 2012
Buku Teks
Sturrock, Ford
Pitman, 1982
Buku Teks
Yang, W.Y.
Food and Agriculture Organization of the United Nations , 1968
Buku Teks
Kay, Ronald D.
McGraw-Hill, 1994
Buku Teks
by Collin J. Watson [and others]
Allyn and Bacon, 1993
Buku Teks