Kettell, Brian, author
John Wiley & Sons, 2011
Buku Teks
Diani Lestari, author
Program Pascasarjana Universitas Indonesia, 2016
UI - Tesis (Membership)
Thorne, W.J., author
Oxford University Press , 1948
Buku Teks
Bradford, Frederick A., author
Longmans, Green, 1932
Buku Teks
Rodgers, Raymond, author
Alexander Hamiltion Institute, 1962
Buku Teks