Osborne, George Edward
West Publishing, 1951
Buku Referensi
Green, Richard
Academic Press, 2014
eBooks
Hart, Samuel L.
Philosophical Library, 1949
Buku Teks SO
Johnson, Alexender Sryan
Dover, 1968
Buku Teks SO
Reisman, George
Jemeson Books, 1998
Buku Teks