@article{MZ_1975__143_172207,
     author = {Mustafa Akcoglu},
     title = {Positive {Contractions} of {L2-Spaces.}},
     journal = {Mathematische Zeitschrift},
     pages = {5--14},
     year = {1975},
     volume = {143},
     zbl = {0307.47005},
     url = {http://geodesic.mathdoc.fr/item/MZ_1975__143_172207/}
}