Bone, Hough Alvin, author
McGraw-Hill, 1981
Buku Teks
League of Women Voters of the United States 1961, 1962
Buku Teks
Hugn A. Bone
McGraw-Hill , 1976
Buku Teks
Stokes, Susan Carol, author
Cambridge University Press, 2014
eBooks
Asher, Herbert B., author
The Dorsey Press, 1980
Buku Teks