@article{FORUM_1992__4_6_141681,
     author = {Michihiro Nagase and Tomio Umeda},
     title = {The nonrelativistic limit for the {Weyl} quantized {Hamlitonians} and pseudo-differential operators.},
     journal = {Forum mathematicum},
     pages = {377--382},
     publisher = {mathdoc},
     volume = {4},
     number = {6},
     year = {1992},
     zbl = {0755.35161},
     url = {http://geodesic.mathdoc.fr/item/FORUM_1992__4_6_141681/}
}