Butler, David
Futura Publications, 1982
Buku Teks SO
Hart, Henry H.
Stanford University Press, 1947
Buku Teks SO
Benedetto, L.F.
Routledge and Kegan Paul, 1950
Buku Teks SO
Novi Diah Haryanti
Fakultas Ilmu Pengetahuan dan Budaya Universitas Indonesia, 2011
UI - Tesis Open
Jonathan Cape, 1928
Buku Teks