@article{MS2_1967__20_165980,
     author = {Egil Heistad},
     title = {Excision in {Singular} {Theory.}},
     journal = {Mathematica Scandinavica},
     pages = {61--64},
     publisher = {mathdoc},
     volume = {20},
     year = {1967},
     zbl = {0175.20101},
     url = {http://geodesic.mathdoc.fr/item/MS2_1967__20_165980/}
}