1. A Survey of the Literature on the Vibrations of Thin Shells;Hu,1964
2. Free Vibrations of Conical Shells;Hu;NASA TN D-2666,1965
3. Free Vibrations of Conical Shells;Federhofer;NASA TT F-8261,1962
4. Small Oscillations of Thin Resilient Conical Shells;Grigolyuk;NASA TT F-25,1960