Flesch, Rudolf, author
Harper & Brothetrs, 1960
Buku Teks
Reader's Digest Service, 1987
Buku Teks
Posner, Richard A., author
Harvard University Press, 2008
Buku Teks
Smith, Daniel, author
Michael O'Mara Books Limited, 2021
Buku Teks
Westwood, John, author
Gramedia, 2006
Buku Teks