Wade, E.C.S. (Emlyn Capel Stewart)
Longmans Green, 1951
Buku Teks
Schmitt, Carl
Duke University Press, 2008
Buku Teks
Kortmann, C.A.J.M.
Kluwer Law International, 2007
Buku Teks
Landsberg, Brian K.
Thomson/West, 2007
Buku Teks
Laurel, Jose P.
Lyceum Press, 1966
Buku Referensi