@article{IM_1985__79_143212,
     author = {J.H.M. Steenbrink},
     title = {Semicontinuity of the singularity spectrum.},
     journal = {Inventiones mathematicae},
     pages = {557--566},
     year = {1985},
     volume = {79},
     zbl = {0568.14021},
     url = {http://geodesic.mathdoc.fr/item/IM_1985__79_143212/}
}