@article{MS2_1979__44_166639,
     author = {Christian F. Skau},
     title = {Positive self-adjoint extensions of operators affiliated with a von {Neumann} algebra.},
     journal = {Mathematica Scandinavica},
     pages = {171--195},
     publisher = {mathdoc},
     volume = {44},
     year = {1979},
     zbl = {0414.46041},
     url = {http://geodesic.mathdoc.fr/item/MS2_1979__44_166639/}
}