Williams, Marta
New World Library, 2003
Buku Teks
Scott, John Paul
University of Chicago Press, 1958
Buku Teks
edited by H.H. Shorey, John J. McKelvey
John Wiley & Sons, 1977
Buku Teks
Tinberger, Niko
Time Life Book, 1970
Buku Teks
Alcock, John
Sinauer Associates, 1989
Buku Teks