APA (7th ed.) Citation

Shrock, R. R., & Twenhofel, W. H. (1989). Principles of invertebrate paleontology (2nd ed.). CBS Publishers & Distributors.

Chicago Style (17th ed.) Citation

Shrock, Robert R., and William H. Twenhofel. Principles of Invertebrate Paleontology. 2nd ed. Delhi: CBS Publishers & Distributors, 1989.

MLA (9th ed.) Citation

Shrock, Robert R., and William H. Twenhofel. Principles of Invertebrate Paleontology. 2nd ed. CBS Publishers & Distributors, 1989.

Warning: These citations may not always be 100% accurate.