edited by Louis G. Locke, William M. Gibson and George W. Arms
Holt, Rinehart and Winston, 1967
Buku Teks SO
Dean, Mitchell, 1955-
Routledge, 1991
Buku Teks
edited by George Dearborn Spindler
Holt, Rinehart and Winston, 1974
Buku Teks SO
Severinghaus, Aura E.
McGraw-Hill , 1953
Buku Teks SO
Snedden, Billy Mackie
Macmillan, 1990
Buku Teks SO