@article{MAN_1965__162_161342,
     author = {H.H. SCHAEFER},
     title = {\"Uber das {Randspektrum} positiver {Operatoren.}},
     journal = {Mathematische Annalen},
     pages = {289--293},
     publisher = {mathdoc},
     volume = {162},
     year = {1965},
     zbl = {0151.19802},
     url = {http://geodesic.mathdoc.fr/item/MAN_1965__162_161342/}
}