Stuart, Graham Henry, 1887-, author
Appleton-Century-Crofts, 1952
Buku Teks
Pan-Pacific Press, 1958
Buku Teks
Barclay, Glen St. John, 1930-, author
Oxford University Press, 1985
Buku Teks
Friedrich, Carl J., author
Boston University Press, 1967
Buku Teks
Salisbury, Harrison E., author
Atheneum, 1965
Buku Teks