Artikel Jurnal
Ministry of forestry forestry research and development agency ,
Majalah, Jurnal, Buletin
Universitas Indonesia, 1997
UI - Skripsi (Membership)
Schreier, Stefan, author
John Wiley & Sons, 1982
Buku Teks
White, Frank M., author
McGraw-Hill, 2006
Buku Teks