@article{MAN_1991__291_1_164885,
     author = {Toshiyuki Katsura and Yuji Shimizu},
     title = {Complex cobordism ring and conformal field theory over {Z.}},
     journal = {Mathematische Annalen},
     pages = {551--572},
     publisher = {mathdoc},
     volume = {291},
     number = {1},
     year = {1991},
     url = {http://geodesic.mathdoc.fr/item/MAN_1991__291_1_164885/}
}