Cartan Elie, La theorie des groupes finis et continus et la geometrie differentielle. Gauthiers-Villars, 1937.
Cartan Elie, La methode du repere mobile, la theorie des groupes continus et les espaces generalises. Hermann, 1935.
B. Outras referências mais actuais e avançadas (que eu não vou abordar):
Griffiths P., On Cartan's method of Lie groups and moving frames as applied to uniqueness and existence questions in differential geometry. Duke Math. Journal 41 (1974), 775-814.
Griffiths P., Harris J., Algebraic geometry and local differential geometry. Ann. Sci. Ecole Norm. Sup. 12 (1979), 355-452.
Akivis M. A., Goldberg V. V., Projective differential geometry of submanifolds. North-Holland, 1993.
Akivis M. A., Goldberg V. V., Conformal differential geometry and its generalizations. John Wiley and Sons, Inc., 1996.
C. Aplicações (que eu não vou abordar):
Razumov A. V., Frenet Frames and Toda Systems, math.DG/9901023
Fels, M., Olver, P. J., Moving coframes I. A practical algorithm. Acta Appl. Math. 51 (1998) 161-213.
Fels, M., Olver, P. J., Moving coframes II. Regularization and theoretical foundations. Acta Appl. Math. 55 (1999) 127-208.
I will explain how geometric descriptions of genera determine geometric descriptions of the associated cohomology theories and then give some examples. Then I will try to say something about the case of elliptic genera. For these the geometric description is still not rigorous.
References (I have copies of the non-web references, in case any one is interested):
Haven't looked at this paper but it has a cool title: Dijkgraaf, R.; Moore, G.; Verlinde, E.; Verlinde, H., Elliptic genera of symmetric products and second quantized strings. Comm. Math. Phys. 185 (1997), no. 1, 197--209. hep-th/9608096
Witten, Ed., Elliptic genera and quantum field theory. Comm. Math. Phys. 109 (1987), no. 4, 525--536. Postscript from KEK library
Hopkins, Michael J. Characters and elliptic cohomology. Advances in homotopy theory (Cortona, 1988), 87--104, London Math. Soc. Lecture Note Ser., 139, Cambridge Univ. Press, Cambridge-New York, 1989
M. J. Hopkins, M. Ando, and N. P. Strickland, "Elliptic spectra, the Witten genus, and the theorem of the cube", dvi file