@article{MZ_1989__201_4_174041,
     author = {Jan Stevens},
     title = {On the ?-constant {Stratum} and the {V-filtration:} an {Example.}},
     journal = {Mathematische Zeitschrift},
     pages = {139--144},
     publisher = {mathdoc},
     volume = {201},
     number = {4},
     year = {1989},
     zbl = {0649.32016},
     url = {http://geodesic.mathdoc.fr/item/MZ_1989__201_4_174041/}
}