Roscoe, Edwin Scott
Richard D. Irwin, 1955
Buku Teks SO
Roscoe, Edwin Scott
Richard D. Irwin, 1959
Buku Teks SO
Woodward, Joan
Oxford University Press, 1965
Buku Teks
Lawrence L. Bethel ... [et al.]
McGraw-Hill, 1954
Buku Teks SO
Seckler-Hudson, Catheryn
Washington, D.C., The American University Press
Buku Teks SO