@article{ELMA_1989__44_3_141463,
     author = {R. Vyborny and R. Nester},
     title = {L'H\^opital's rule, a counterexample.},
     journal = {Elemente der Mathematik},
     pages = {116--121},
     year = {1989},
     volume = {44},
     number = {3},
     zbl = {0702.26003},
     url = {http://geodesic.mathdoc.fr/item/ELMA_1989__44_3_141463/}
}