@article{NSJOM_2013_43_1a_6,
     author = {Prem Nath, and Dhiraj Kumar Singh},
     title = {On a sum form functional equation and its relevance\\ in
 information theory and cryptanalysis},
     journal = {Novi Sad Journal of Mathematics},
     pages = {59-71},
     publisher = {mathdoc},
     volume = {43},
     number = {1},
     year = {2013},
     url = {http://geodesic.mathdoc.fr/item/NSJOM_2013_43_1a_6/}
}