Basch, Lester D.
Spelling self-taught: a teaching-machine book
Sterling Publishing, 1962
 Buku Teks SO
Carney, Edward, translator
English spelling/ Edward Carney
Routledge,, 1997
 Buku Teks SO
Furness, Edna L.
Spelling for the millions
Appleton Century , 1964
 Buku Teks SO
Mudd, Norma
Effective spelling : a practical guide for teachers / Norma Mudd
Hodder & Stoughton Educational , 1998
 Buku Teks
Mustakim
Tanya jawab ejaan Bahasa Indonesia untuk umum
Gramedia Pustaka, 1996
 Buku Teks SO