The Association for Supervision and Curriculum Development, 1978
Buku Teks
Hawley, Amos H., author
The University of Chicago Press, 1986
Buku Teks
Zipf, George Kingsley, author
Hafner, 1965
Buku Teks
edited by Gwen Bell
Hawaii University Press, 1976
Buku Teks
Hawley, Amos H., author
The Ronald Press, 1950
Buku Teks