Auburn House Publ., 1982
Buku Teks
Unesco , 1952
Buku Teks
by George C. Atteberry ... [at al.]
Macmillan, 1950
Buku Teks
Blalock, Hubert M., author
Sage Publications, 1982
Buku Teks
Rosenberg, Alexander, author
John Hopkins University Press, 1980
Buku Teks