%0 Journal Article
%A Arthur W. Apter
%T $L$-like Combinatorial Principles  and Level by Level Equivalence
%J Bulletin of the Polish Academy of Sciences. Mathematics
%D 2009
%P 199-207
%V 57
%N 3
%I mathdoc
%U http://geodesic.mathdoc.fr/articles/10.4064/ba57-3-2/
%R 10.4064/ba57-3-2
%G en
%F 10_4064_ba57_3_2