@article{AM2_1987__34_137248,
     author = {Heinz Leutwiler},
     title = {Best constants in the {Harnack} inequality for the {Weinstein} equation.},
     journal = {Aequationes mathematicae},
     pages = {304--315},
     publisher = {mathdoc},
     volume = {34},
     year = {1987},
     zbl = {0653.31002},
     url = {http://geodesic.mathdoc.fr/item/AM2_1987__34_137248/}
}