@article{10_4153_CMB_1967_023_x,
     author = {Marsden, J. E.},
     title = {A {Correspondence} {Principle} for {Momentum} {Operators}},
     journal = {Canadian mathematical bulletin},
     pages = {247--250},
     year = {1967},
     volume = {10},
     number = {2},
     doi = {10.4153/CMB-1967-023-x},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1967-023-x/}
}