@article{MAT_1961_5_3_a3,
     author = {E. Nelson and F. Stinespring},
     title = {Representation of elliptic operators in an enveloping algebra},
     journal = {Matematika},
     pages = {81--94},
     publisher = {mathdoc},
     volume = {5},
     number = {3},
     year = {1961},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MAT_1961_5_3_a3/}
}