@article{MZ_1957__68_169698,
     author = {Elmar Thoma},
     title = {Zur {Reduktionstheorie} in allgemeinen {Hilbert-R\"aumen.}},
     journal = {Mathematische Zeitschrift},
     pages = {153--188},
     publisher = {mathdoc},
     volume = {68},
     year = {1957},
     zbl = {0199.19404},
     url = {http://geodesic.mathdoc.fr/item/MZ_1957__68_169698/}
}