Gallup, George
McGraw-Hill, 1982
Buku Teks SO
Neimark, Edith D.
Harcourt Brace Javanovich, 1987
Buku Teks SO
Whitehead, Alfred North, 1861-1947
The New American Library, 1933
Buku Teks
Lucie-Smith, Edward
Thames and Hudson, 1994
Buku Teks
Rowe, Peter G.
MIT Press, 1997
Buku Teks SO