%0 Book Section %A Slawny, J. %T Phase transitions in ferromagnetic spin systems at low temperatures %B International conference on dynamical systems in mathematical physics %A Collectif %S Astérisque %D 1976 %P 181-182 %N 40 %I Société mathématique de France %U http://www.numdam.org/item/AST_1976__40__181_0/ %G en %F AST_1976__40__181_0