Nepal : National Conservation Strategy Implementation Project, 1992,
Buku Referensi
Bank Indonesia dan Banco de Mexico, 2008
Buku Teks
Jakarta Pusat Penelitian Sumber daya Manusia dan Lingkungan Hidup UI 1991,
Buku Teks
edited by Pierre A. Gremaud, Zhilin Li, Ralph C. Smith, Hien T. Tran
Society for Industrial and Applied Mathematics, 2000
eBooks
edited by Madan G. Singh and Andre Titli
Pergamon Press, 1978
Buku Teks