Shrock, R. R. T. (1953). Principles of invertebrate paleontology (2.). McGrawhill.
Chicago Edition CitationShrock, Robert R Twenhofel. Principles of Invertebrate Paleontology. 2. NY: McGrawhill, 1953.
MLA Edition CitationShrock, Robert R Twenhofel. Principles of Invertebrate Paleontology. 2. McGrawhill, 1953.
Warning: These citations may not always be 100% accurate.