Graham & Trotman, 1987
Buku Teks
Keeton, Robert E., author
West Publishing, 1988
Buku Teks
Hohmann, Harald, author
Martinus Nijhoff, 1994
Buku Teks
Doris, Lillian
Prentice-Hall, 1951
Buku Teks
Nasution, Rido Akmal, author
2016
UI - Tesis (Membership)