%D 1969 %L acta14213 %J Acta scientiarum mathematicarum %T A note on the existence of derivations %P 89-92 %O Bibliogr.: 92. p. %A Loy Richard J. %N 1-2 %V 30 %K TermĂŠszettudomĂĄny, Matematika, MĹąvelĹdĂŠs