Katrina Brown ... [et al.]
The Global Environment Facility, 1993
Buku Teks
Spellerberg, Ian F.
Cambridge University Press, 1992
Buku Teks
edited by Hugh Synge
John Wiley & Sons, 1981
Buku Teks
Kantor Menteri Negara Kependudukan dan Lingkungan Hidup, 1992
Buku Referensi
edited by Michael E. Soule
Sinauer Associates, 1986
Buku Teks