1
2
by Ehrlich, Paul R.
Published 1970
3
4
by Goldscheider, Calvin
Published 1996
5
Published 1985
6
Published 1971
7
by Longva, Anh Nga
Published 1997
8
by Zhang, Guoqing
Published 2006
9
10
by Russell, Edward J, 1872-1965
Published 1954
11
by Saw, Swee-Hock, 1931-
Published 2007
12
Published 1986
13
by Saw, Swee-Hock
Published 1988
14
Published 1992
15
by Sanderson, Warren C.
Published 1996
16
Published 1993
17
by Saw Swee-Hock
Published 2005
18
by McKee, David L.
Published 1990
19
20
by Boserup, Ester
Published 1990