H Veenman En Zonen B.V, 1980
Majalah, Jurnal, Buletin
Black, Jaquelyn G., author
John Wiley & Sons, 2008
Buku Teks
Stanier, Roger Y., author
Prentice-Hall, 1963
Buku Teks
Burrows, William E., author
W.B. Saunders, 1959
Buku Teks
Brock, Thomas D., author
Prentice-Hall, 1973
Buku Teks