APA (7th ed.) Citation

Siedel, F., & Siedel, J. M. (1968). Pioneers in science. Houghton Mifflin.

Chicago Style (17th ed.) Citation

Siedel, Frank, and James M. Siedel. Pioneers in Science. Boston: Houghton Mifflin, 1968.

MLA (9th ed.) Citation

Siedel, Frank, and James M. Siedel. Pioneers in Science. Houghton Mifflin, 1968.