David, Rene, 1906-
Stevens & sons, 1985
Buku Teks SO
Erades, Judge
Martinus Nijhoff Publishers, 1983
Buku Teks
Fox, James R.
Oceana Publication, 1992
Buku Referensi
Roux, Theunis
Cambridge University Press, 2018
eBooks
Glendon, Mary Ann
West Academic Publishing, 1999
Buku Teks