Moorad, George
E.P. Duttom, 1949
Buku Teks SO
Chanlett, Emil T.
McGraw-Hill, 1979
Buku Teks
United Nations Conference on Human Environment, 1972
Buku Teks SO
Qi, Wen
Foreign Languages Press, 1989
Buku Teks SO
Chen, Kenneth K.S.
Princeton Un iversity Press, 1964
Buku Teks SO