Brownell, Baker
Harper & Brothers Publishers , 1950
Buku Teks
Bahm, Archie J.
Archie J. Bahm, 1985
Buku Teks
Baruch, Bernard M.
Sinmon and Schuster, 1954
Buku Teks SO
Weston, Michael
Routledge , 2001
Buku Teks SO
Chu, Hsi
Probsthain, 1922
Buku Teks SO