Go, Julian, author
Oxford University Press, 2016
eBooks
Teo, Thomas, author
Springer, 2005
Buku Teks
Phillips, D.C., author
Stanford University Press, 1976
Buku Teks
United Nations Bureau of Social Affairs , 1955
Buku Teks
Benton, Ted, author
Palgrave Macmillan, 2011
Buku Teks