%0 Journal Article %A Poljak, Svatopluk %A TurzĂ­k, Daniel %T On amalgamation of graphs and essential sets of generators %J Commentationes Mathematicae Universitatis Carolinae %D 1978 %P 359-369 %V 19 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/CMUC_1978__19_2_a11/ %G en %F CMUC_1978__19_2_a11