@article{MZ_1974__136_172044,
     author = {Dorin Ghisa},
     title = {Remarks on {Hersch-Pfluger} {Theorem.}},
     journal = {Mathematische Zeitschrift},
     pages = {291--294},
     publisher = {mathdoc},
     volume = {136},
     year = {1974},
     zbl = {0271.30027},
     url = {http://geodesic.mathdoc.fr/item/MZ_1974__136_172044/}
}