%0 Journal Article %A K.D. jr. Magill %A B.B. Baird %T Green's ...-relation and climbing mountains. %J Semigroup forum %D 1979 %P 347-370 %V 18 %I mathdoc %U http://geodesic.mathdoc.fr/item/SF_1979__18_134365/ %F SF_1979__18_134365