@article{CMH_1966__41_139323,
     author = {Burckart C. Kind},
     title = {Eine {Zuordnung} von {Operatoren} zu {Funktionen.}},
     journal = {Commentarii mathematici Helvetici},
     pages = {237--260},
     year = {1966},
     volume = {41},
     zbl = {0172.40603},
     url = {http://geodesic.mathdoc.fr/item/CMH_1966__41_139323/}
}