@article{10_4064_ap_48_2_153_165,
     author = {Pl. Kannappan},
     title = {On a generalization of the sum form functional equation. {VI}},
     journal = {Annales Polonici Mathematici},
     pages = {153--165},
     publisher = {mathdoc},
     volume = {48},
     number = {2},
     year = {1988},
     doi = {10.4064/ap-48-2-153-165},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/ap-48-2-153-165/}
}