Principles of invertebrate paleontology - Twenhofel, William H. (William Henry), 1875-1957.; Shrock, Robert R. (Robert Rakes), 1904-1993 (New York, McGraw-Hill, 1953)
"A revised and enlarged edition of Twenhofel and Shrock, Invertebrate paleontology."
Keywords: Invertebrates, Fossil