@article{MS2_1978__43_166625,
     author = {Esben T. Kehlet},
     title = {A proof of the {Mackey-Blattner-Nielsen} theorem.},
     journal = {Mathematica Scandinavica},
     pages = {329--335},
     publisher = {mathdoc},
     volume = {43},
     year = {1978},
     zbl = {0426.22008},
     url = {http://geodesic.mathdoc.fr/item/MS2_1978__43_166625/}
}