%0 Journal Article %A Grätzer, George %T Using the Swing Lemma and \( \mathcal{C}_1 \)-diagrams for congruences of planar semimodular lattices %J Discussiones Mathematicae. General Algebra and Applications %D 2023 %P 63-74 %V 43 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/DMGAA_2023_43_1_a5/ %G en %F DMGAA_2023_43_1_a5