1. Behre, Jr. C.H., Slate in Pennsylvania. Penn. Geol. Surv., Bull. M., 4 Ser., 16: 400 pp.
2. Structural Geology;Billings,1954
3. Reservoir pressures in Gulf Coast, Louisiana;Dickinson;Bull. Am. Assoc. Petrol. Geologists,1953
4. Gravitational compaction of clays and shales;Hedberg;Am. J. Sci., 5 Ser.,1936
5. Elements of Structural Geology;Hills,1963