Kelly, Gery F.
McGraw-Hill, Higher Education, 2008
Buku Teks SO
Sanders, Donald H.
McGraw-Hill, 1983
Buku Teks SO
Steele, James
Phaidon Press, 1997
Buku Teks SO
McCune, George M.
Harvard University Press, 1950
Buku Teks SO
Buckley, Roger
Cambridge University Press, 1990
Buku Teks SO