@article{MZ_1980__174_173009,
     author = {Neil S. Trudinger},
     title = {On the {First} {Eigenvalue} of {Non-Uniformly} {Elliptic} {Boundary} {Value} {Problems.}},
     journal = {Mathematische Zeitschrift},
     pages = {227--232},
     publisher = {mathdoc},
     volume = {174},
     year = {1980},
     zbl = {0439.35053},
     url = {http://geodesic.mathdoc.fr/item/MZ_1980__174_173009/}
}