1. L. P. Eisenhart:Riemannian Geometry (Princeton, N.J., 1966).
2. L. P. Eistenhart:Non-Riemannian Geometry, American, Mathematical Society, Colloquium VIII (1927).
3. K. H. Mariwalla:Journ. Math. Phys.,12, 96 (1971).
4. See,e.g.,J. L. Synge:Handbuch der Physik, Vol.3.1 (Berlin, 1960), p. 139; or ref. (5), p. 278.
5. L. P. Eisenhart:Continuous Groups of Transformations (Dover, N. Y., 1961).