TY  - BOOK
AU  - Twenhofel, William Henry
AU  - Shrock, Robert Rakes
TI  - PRINCIPLES OF INVERTEBRATE PALEONTOLOGY
U1  - 562 
PY  - 1953///
CY  - N. Y.
PB  - Mcgraw-Hill
KW  - Invertebrates, Fossils
ER  -