APA (7th ed.) Citation

Thomson, J. W. (1963). The lichen genus Physcia in North America. J. Cramer.

Chicago Style (17th ed.) Citation

Thomson, John Walter. The Lichen Genus Physcia in North America. Weinheim: J. Cramer, 1963.

MLA (9th ed.) Citation

Thomson, John Walter. The Lichen Genus Physcia in North America. J. Cramer, 1963.