@article{CM_1976__33_1_15_0,
     author = {Singh, Balwant},
     title = {A numerical criterion for the permissibility of a blowing-up},
     journal = {Compositio Mathematica},
     pages = {15--28},
     publisher = {Noordhoff International Publishing},
     volume = {33},
     number = {1},
     year = {1976},
     mrnumber = {419435},
     zbl = {0335.14003},
     language = {en},
     url = {http://www.numdam.org/item/CM_1976__33_1_15_0/}
}