@article{10_1017_S0017089500002147,
     author = {Ching, Chin-Hung and Chui, Charles K.},
     title = {Delange's characterization of the sine function},
     journal = {Glasgow mathematical journal},
     pages = {66--68},
     year = {1974},
     volume = {15},
     number = {1},
     doi = {10.1017/S0017089500002147},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500002147/}
}