@article{MZ_1970__115_171360,
     author = {John D. DePree and John A. Higgins},
     title = {Collectively {Compact} {Sets} of {Linear} {Operators.}},
     journal = {Mathematische Zeitschrift},
     pages = {366--370},
     publisher = {mathdoc},
     volume = {115},
     year = {1970},
     zbl = {0188.19602},
     url = {http://geodesic.mathdoc.fr/item/MZ_1970__115_171360/}
}