APA (7th ed.) Citation

Heyl, A. V., & McKeown, F. A. (1978). Preliminary seismotectonic map of the central Mississippi Valley and environs. The Survey.

Chicago Style (17th ed.) Citation

Heyl, Allen V., and F. A. McKeown. Preliminary Seismotectonic Map of the Central Mississippi Valley and Environs. Reston, Va.: The Survey, 1978.

MLA (9th ed.) Citation

Heyl, Allen V., and F. A. McKeown. Preliminary Seismotectonic Map of the Central Mississippi Valley and Environs. The Survey, 1978.