Metcalf, John E., author
U.S. Department of Agriculture , 1952
Buku Teks
Research Institute Of Udayana University, 1997
Buku Referensi
edited by John F. Griffith
Oxford University Press, 1994
Buku Referensi
Koninlijk Institut voor de Tropen, 1992,
Majalah, Jurnal, Buletin
Norton, George W., author
McGraw-Hill, 1993
Buku Teks