%0 Journal Article
%A Grätzer, George
%T Notes on planar semimodular lattices IX \( \mathcal{C}_1 \)-diagrams
%J Discussiones Mathematicae. General Algebra and Applications
%D 2023
%P 25-29
%V 43
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DMGAA_2023_43_1_a1/
%G en
%F DMGAA_2023_43_1_a1