@article{AM2_1992__43_1_137463,
     author = {Jens Schwaiger},
     title = {On generalized hyperbolic functions and their characterization by functional equations.},
     journal = {Aequationes mathematicae},
     pages = {198--210},
     publisher = {mathdoc},
     volume = {43},
     number = {1},
     year = {1992},
     zbl = {0755.39009},
     url = {http://geodesic.mathdoc.fr/item/AM2_1992__43_1_137463/}
}