1. Buckling of variable cross-section columns — Integral-equation approach;Arbabei;ASCE, J. Struct. Engng.,1991
2. N,. Design of columns of varying cross section;Dinnik;Trans ASME,,1929
3. Structural stability of columns and plates;Iyengar,1988
4. Differentialgleichungen, Lösungsmethoden und Lösungen, Vol. 1;Kamke,1971
5. Mathematical methods in engineering;Karman,1940