@article{GDZPPN002550385, title = {On a theorem of B. Barna.}, journal = {Aequationes mathematicae}, volume = {20}, year = {1980}, pages = {173-178}, zbl = {0487.26001}, url = {http://dml.mathdoc.fr/item/GDZPPN002550385} }
Kuczma, Marek. On a theorem of B. Barna.. Aequationes mathematicae, Tome 20 (1980) pp. 173-178. http://gdmltest.u-ga.fr/item/GDZPPN002550385/