1. Abraham R. and Marsden J. E., Foundations of Mechanics, 2nd ed., Addison-Wesley Publishing Co., Reading, Mass., 1978.
2. Arnold V. I., Sur la géométrie différentielle des groupes de Lie de dimension infinie et ses applications à l’hydrodynamique des fluides parfaits, Ann. Inst. Fourier, Grenoble 16 (1) (1966), 319–361.
3. Concus P. and Finn R., The shape of a pendent liquid drop, Philos. Trans. Roy. Soc. London Ser. A, 292 (1979), 307–340.
4. Progress in Astronautics and Aeronautics;P Concus,1990
5. Crandall M. G. and Rabinowitz P. H., Bifurcation from simple eigenvalues, J. Funct. Anal. 8 (1971), 321–340.