@article{10_1090_S0894_0347_98_00250_1,
     author = {Li, Jun and Tian, Gang},
     title = {Virtual moduli cycles and {Gromov-Witten} invariants of algebraic varieties},
     journal = {Journal of the American Mathematical Society},
     pages = {119--174},
     publisher = {mathdoc},
     volume = {11},
     number = {1},
     year = {1998},
     doi = {10.1090/S0894-0347-98-00250-1},
     url = {http://geodesic.mathdoc.fr/articles/10.1090/S0894-0347-98-00250-1/}
}