%0 Journal Article %A Salvatore, A. %T Solutions of minimal period of a wave equation via a generalization of a Hofer's theorem %J Rendiconti del Seminario Matematico della Università di Padova %D 1989 %P 49-63 %V 81 %I Seminario Matematico of the University of Padua %U http://www.numdam.org/item/RSMUP_1989__81__49_0/ %G en %F RSMUP_1989__81__49_0