1. COOPER, G.A., THE SCIENCE OF PALEONTOLOGY - PRESIDENTIAL ADDRESS, JOURNAL OF PALEONTOLOGY 32: 1010 (1958).
2. COX, L.R., BIVALVE GASTROPOD, NATURE 185: 749 (1960).
3. Cutbill, J. L., The Fossil Record: 791 (1967).
4. DURHAM, J.W., J PALEONTOL 41: 559 (1967).
5. Probability 1970