Antonini, P., Marmo, G., and Rubano, C. (1985).Nuovo Cimenta B,86, 17.
Atherton, R. W., and Homsy, G. M. (1975).Studies in Applied Mathematics,54, 31.
Bahar, L. Y., and Kwatny, H. G. (1984).Mechanics Research Communications,11, 253.
Carinena, J. F., and Ibort, L. A. (1985).Physics Letters,107A, 356.
Caviglia, G. (1983a).Journal of Mathematical Physics,24, 2065.
Caviglia, G. (1983b).International journal of Theoretical Physics,22, 1051.
Caviglia, G. (1984).International Journal of Theoretical Physics,23, 461.
Caviglia, G. (1985a).Inverse Problems,1, L13.
Caviglia, G. (1985b).International Journal of Theoretical Physics,24, 377.
Crampin, M. (1980).Physics Letters,79A, 138.
Crampin, M. (1981).Journal of Physics A: Mathematical Nuclear and General,14, 2567.
Crampin, M. (1983).Physics Letters,95A, 209.
De Filippo, S., Vilasi, G., Marmo, G., and Salerno, M. (1984).Nuovo Cimenta B,83, 97.
Gonzalez-Gascon, F., and Rodriguez-Camino, E. (1980).Letter al Nuovo Cimento,29, 113.
Greenberger, D. M. (1979).Journal of Mathematical Physics,20, 762.
Hojman, S., and Urrutia, R. F. (1981).Journal of Mathematical Physics,22, 1896.
Leipholz, H. H. E. (1980). InTheoretical and Applied Mechanics. North-Holland, Amsterdam, p. 1.
Morse, P. M., and Feshbach, H. (1953).Methods of Theoretical Physics, Vol. 1. McGraw-Hill, New York, p. 298.
Prince, G. E., and Crampin, M. (1984).General Relativity Gravitation,16, 921.
Santilli, R. M. (1978).Foundations of Theoretical Mechanics I. The Inverse Problem in Newtonian Mechanics. Springer, New York.
Sarlet, W., and Cantrijn, F. (1981).Siam Review,23, 467.
Schattner, R., and Trumper, M. (1981).Journal of Physics A: Mathematics General and Nuclear,14, 2345.
Thangaray, D., and Venkatarangan, S. N. (1983).IMA Journal of Applied Mathematics,30, 21.
Tikochinsky, Y. (1978).Journal of Mathematical Physics,19, 888.
Trumper, M. (1980).Comptes Rendus Hebdomadaires des Seances de l' Academie des Sciences Paris,291, 615.
Trumper, M. (1983).Annals of Physics (New York),149, 203.
