%0 Journal Article
%A Rival, Ivan
%A Sands, Bill
%T Planar Sublattices of a Free Lattice. II
%J Canadian journal of mathematics
%D 1979
%P 17-34
%V 31
%N 1
%U http://geodesic.mathdoc.fr/articles/10.4153/CJM-1979-003-8/
%R 10.4153/CJM-1979-003-8
%F 10_4153_CJM_1979_003_8