1. T. von Kármán, Ency. Math. Wiss. 4, No. 4, 348–352 Teubner, Leipzig. 191C
2. The non-linear boundary value problem of the buckled plate;Friedrichs, K. O.;Amer. J. Math.,1941
3. Heavy rotating string—a nonlinear eigenvalue problem;Kolodner, Ignace I.;Comm. Pure Appl. Math.,1955
4. G. H. Pimbley, J. Math. Mech. 10, Jan. 1962
5. The shape of the strongest column;Keller, Joseph B.;Arch. Rational Mech. Anal.,1960