Geary, David M.
Prentice-Hall, 1997
Buku Teks SO
arranged and edited by Wolfgang Hageney
Belvedere, 1989
Buku Teks SO
Bob Gordon, consultant editor; Maggie Gordon, consultant editor
Watson-Guptill Publications, 2002
Buku Teks SO
French, Thomas Ewing, 1871-1944
McGraw-Hill, 1984
Buku Teks SO
Hill, Francis S.
Macmillan, 1990
Buku Teks SO