Lewis, Norman
Dictionary of correct spelling : a handy reference guide
Harper & Row, 1962
Buku Referensi
Basch, Lester D.
Spelling self-taught: a teaching-machine book
Sterling Publishing, 1962
Buku Teks SO
Carney, Edward
English spelling/ Edward Carney
Routledge, 1997
Buku Teks SO
Furness, Edna L.
Spelling for the millions
Appleton Century , 1964
Buku Teks SO
Radlauer, Ruth
Teachers guide reading incentive
Bowmar, 1971
Buku Teks SO