@article{10_1007_s10492_006_0018_6,
     author = {Nath, Prem and Singh, Dhiraj Kumar},
     title = {On a multiplicative type sum form functional equation and its role in information theory},
     journal = {Applications of Mathematics},
     pages = {495--516},
     publisher = {mathdoc},
     volume = {51},
     number = {5},
     year = {2006},
     doi = {10.1007/s10492-006-0018-6},
     mrnumber = {2261636},
     zbl = {1164.39330},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.1007/s10492-006-0018-6/}
}