APA (7th ed.) Citation

Blackstone, E. G., & Smith, S. L. (1949). Improvement of instruction in typewriting (Second edition.). Prentice-Hall.

Chicago Style (17th ed.) Citation

Blackstone, E. G., and Sofronia Lucretia Smith. Improvement of Instruction in Typewriting. Second edition. New York: Prentice-Hall, 1949.

MLA (9th ed.) Citation

Blackstone, E. G., and Sofronia Lucretia Smith. Improvement of Instruction in Typewriting. Second edition. Prentice-Hall, 1949.