Robinson, Marguerite S., author
Cambridge University Press, 1975
Buku Teks
Dac Hammarskjold foundation,
Majalah, Jurnal, Buletin
Anastasiou, Michaelangelo, author
Routledge, 2020
Buku Teks
Harmon, M. Judd
McGraw-Hill, 1964
Buku Teks
Hsuan-yi Chou, author
Artikel Jurnal