Kimball, G. S. (1905). Kimball's business speller: Designed for use in commercial schools, academies, normal schools, high schools & the higher grades of the common schools. The Bobbs-Merrill Company.
Trích dẫn kiểu Chicago (xuất bản lần thứ 7)Kimball, Gustavus Sylvester. Kimball's Business Speller: Designed for Use in Commercial Schools, Academies, Normal Schools, High Schools & the Higher Grades of the Common Schools. Indianapolis: The Bobbs-Merrill Company, 1905.
Trích dẫn kiểu MLA (xuất bản lần thứ 8)Kimball, Gustavus Sylvester. Kimball's Business Speller: Designed for Use in Commercial Schools, Academies, Normal Schools, High Schools & the Higher Grades of the Common Schools. The Bobbs-Merrill Company, 1905.
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