Purba, Imelda, author
Universitas Indonesia, 2014
UI - Skripsi (Membership)
Tainter, Joseph A., author
Springer, 2012
eBooks
Agency for Agricultural Research and Development, 1992
Buku Teks
Agency for Agricultural Research and Development Ministry of Agriculture, 1992
Buku Referensi
McCawley, Peter, author
Asian Development Bank, 2020
Buku Teks