APA (7th ed.) Citation

Sonneck, O. G. (1963). Early opera in America. B. Blom.

Chicago Style (17th ed.) Citation

Sonneck, O. G. Early Opera in America. New York: B. Blom, 1963.

MLA (9th ed.) Citation

Sonneck, O. G. Early Opera in America. B. Blom, 1963.