1. P. S. Aspinwall, D. R. Morrison, Topological field theory and rational curves, Commun. Math. Phys. 151 (1993), 245–262.
2. P. Baum, W. Fulton, R. MacPherson, Riemann-Roch for singular varieties, Publ. Math. I. H. E. S. 45 (1975), 101–145.
3. R. Bott, A residue formula for holomorphic vector fields, Jour. Diff. Geom. 1 (1967), 311–330.
4. P. Deligne, D. Mumford, The irreducibility of the space of curves of given genus, Publ. Math. I. H. E. S. 36 (1969), 75–110.
5. A. Givental, B. Kim, Quantum cohomology of flag manifolds and Toda lattices, preprint (1993).