Collins, Denis, author
John Wiley & Sons, 2009
Buku Teks
Raden Ayu Moza Tammy, author
2018
UI - Skripsi (Membership)
Cornell, William B., author
Alexander Hamilton Institute, 1962
Buku Teks
Ebert, Ronald J., author
Prentice-Hall, 2009
Buku Teks
Tonne, Herbert Arthur, author
McGraw-Hill, 1963
Buku Teks