%0 Journal Article %A Katona, Gyula O.H. %A Tichler, KrisztiƔn %T An extremal problem on trees and database theory %J Discrete mathematics & theoretical computer science %D 2005 %V DMTCS Proceedings vol. AE, European Conference on Combinatorics, Graph Theory and Applications (EuroComb '05) %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.46298/dmtcs.3461/ %R 10.46298/dmtcs.3461 %G en %F DMTCS_2005_special_250_a70