1. BANDY, O.L., THE GEOLOGIC SIGNIFICANCE OF COILING RATIOS IN THE FORAMINIFER GLOBIGERINA-PACHYDERMA (EHRENBERG), JOURNAL OF PALEONTOLOGY 34: 671 (1960).
2. BRAMLETTE, M. N., U.S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 196-A 1 (1940).
3. CUSHMAN, J. A., U.S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 196-A 35 (1940).
4. Note on Gadinia;AMERICAN JOURNAL OF CONCHOLOGY,1872
5. Postglacial Hypsithermal Interval