@article{MZ_1968__107_171053,
     author = {Peter Hess},
     title = {\"Uber die wesentliche {Maximalit\"at} gleichm\"a{\ss}ig stark elliptischer {Operatoren} in {L2} {(Rn).}},
     journal = {Mathematische Zeitschrift},
     pages = {67--70},
     publisher = {mathdoc},
     volume = {107},
     year = {1968},
     zbl = {0159.40201},
     url = {http://geodesic.mathdoc.fr/item/MZ_1968__107_171053/}
}