1. Structural Geology;Billings,1954
2. Folding instability of layered viscoelastic medium under compression;Biot,1957
3. Theory of folding of stratified viscoelastic medium;Biot;J. Franklin Inst.,1961
4. Evolution of ptygmatic folding;Ramberg;Norsk Geol. Tidsskr.,1959
5. Fluid dynamics of viscous buckling applicable to folding of layered rocks;Ramberg;Bull. Am. Assoc. Petrol. Geologists,1963