@article{MOMA_1983__95_178106,
     author = {Josef Nagel},
     title = {Kantorovic {Operators} of {Second} {Order.}},
     journal = {Monatshefte f\"ur Mathematik},
     pages = {33--44},
     publisher = {mathdoc},
     volume = {95},
     year = {1983},
     zbl = {0497.41011},
     url = {http://geodesic.mathdoc.fr/item/MOMA_1983__95_178106/}
}