@article{701639,
     title = {On $\mathcal {C}$-conformal changes of Riemann-Finsler metrics},
     booktitle = {Proceedings of the 18th Winter School "Geometry and Physics"},
     series = {GDML\_Books},
     publisher = {Circolo Matematico di Palermo},
     address = {Palermo},
     year = {1999},
     pages = {221-228},
     mrnumber = {MR1692273},
     zbl = {0966.53051},
     url = {http://dml.mathdoc.fr/item/701639}
}

Vincze, Cs. On $\mathcal {C}$-conformal changes of Riemann-Finsler metrics, dans Proceedings of the 18th Winter School "Geometry and Physics", GDML_Books,  (1999), pp. 221-228. http://gdmltest.u-ga.fr/item/701639/