Watson, J. M., & Parker, R. G. (1868). The national elementary speller: A critical work on pronunciation embracing a strictly graded classification of the primitive and the more important derivative words of the English language for oral spelling, exercises for writing from dictation, prefixes, affixes, &c., &c. A.S. Barnes & Co..

Watson, J. Madison, and Richard Green Parker. The National Elementary Speller: A Critical Work on Pronunciation Embracing a Strictly Graded Classification of the Primitive and the More Important Derivative Words of the English Language for Oral Spelling, Exercises for Writing from Dictation, Prefixes, Affixes, &c., &c. New York: A.S. Barnes & Co., 1868.

Watson, J. Madison, and Richard Green Parker. The National Elementary Speller: A Critical Work on Pronunciation Embracing a Strictly Graded Classification of the Primitive and the More Important Derivative Words of the English Language for Oral Spelling, Exercises for Writing from Dictation, Prefixes, Affixes, &c., &c. A.S. Barnes & Co., 1868.