1. O’Neil MW, Reese LC. Drilled shaft: construction procedures and design methods. FHWA-IF-99-025, 1999.
2. Vertical vibration of embedded footings;Novak;J Soil Mech Found Div ASCE,1972
3. Dynamic stiffness of circular foundations;Kausel;J Eng Mech Div ASCE,1975
4. Elsabee F, Morray JP. Dynamic behavior of embedded foundations. R77-33, MIT, 1977.
5. Dominguez J. Dynamic stiffness of rectangular foundations. R78-20, MIT, 1978.