@article{MS2_1972__31_166265,
     author = {Trond Digernes},
     title = {On {Classes} of {Projections} in a von {Neumann} {Algebra.}},
     journal = {Mathematica Scandinavica},
     pages = {191--200},
     publisher = {mathdoc},
     volume = {31},
     year = {1972},
     zbl = {0252.46074},
     url = {http://geodesic.mathdoc.fr/item/MS2_1972__31_166265/}
}