%0 Journal Article %A Geffert, Viliam %T Normal forms for phrase-structure grammars %J RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications %D 1991 %P 473-496 %V 25 %N 5 %I EDP-Sciences %U http://www.numdam.org/item/ITA_1991__25_5_473_0/ %G en %F ITA_1991__25_5_473_0