@article{10_21136_CMJ_1992_128350,
     author = {Verma, Ram U.},
     title = {Numerical range and related nonlinear functional equations},
     journal = {Czechoslovak Mathematical Journal},
     pages = {503--513},
     year = {1992},
     volume = {42},
     number = {3},
     doi = {10.21136/CMJ.1992.128350},
     mrnumber = {1179314},
     zbl = {0781.47048},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CMJ.1992.128350/}
}