Schregle, Johannes
UP.Law Center, 1975
Buku Teks
Sidek, Azizah
National Library Singapore, 1995
Buku Referensi
Farah Wardani, author
University of Indonesia, Faculty of Humanities, 2019
Artikel Jurnal
Huffman, Franklin E.
Yale University Press, 1986
Buku Referensi
edited by C.D. Cowan and O.W. Wolters
Cornell University Press, 1976
Buku Teks