Business Advisory Indonesia, [Date of publication not identified]
Buku Referensi
Bryson, George D.
Harper & Brothers, 1961
Buku Teks SO
edited by Walter Sterling Surrey and Crawford Shaw
American Law Institute, 1963
Buku Teks SO
edited by Joseph R. Crowley
Fordham University Press , 1962
Buku Teks
Brash, Donald T.
Australian National University , 1966
Buku Teks SO