Ley, Willy
Doubleday and Company, Inc., 1969
Buku Teks
[publisher not identified], 1957
Buku Teks
Sumitro Joyohadikusumo
Institute for Economic and Social Research, Education, and Information, 1977
Buku Teks
Ristek, editor
Gramedia Pustaka Utama, 2009
Buku Teks
Sage Publications , 2018
Majalah, Jurnal, Buletin