Butter, H., & Green, R. W. (1836). The scholar's companion, or, A guide to the orthography, pronunciation and derivation of the English language: Arranged on the basis of the 15th London ed. of Butter's Etymological spelling-book and expositor (2nd ed.). Henry Perkins.

Butter, Henry, and Richard W. Green. The Scholar's Companion, or, A Guide to the Orthography, Pronunciation and Derivation of the English Language: Arranged on the Basis of the 15th London Ed. of Butter's Etymological Spelling-book and Expositor. 2nd ed. Philadelphia: Henry Perkins, 1836.

Butter, Henry, and Richard W. Green. The Scholar's Companion, or, A Guide to the Orthography, Pronunciation and Derivation of the English Language: Arranged on the Basis of the 15th London Ed. of Butter's Etymological Spelling-book and Expositor. 2nd ed. Henry Perkins, 1836.