@article{RSMUP_1989__81__49_0, author = {Salvatore, A.}, title = {Solutions of minimal period of a wave equation via a generalization of a {Hofer's} theorem}, journal = {Rendiconti del Seminario Matematico della Universit\`a di Padova}, pages = {49--63}, publisher = {Seminario Matematico of the University of Padua}, volume = {81}, year = {1989}, mrnumber = {1020185}, zbl = {0696.35109}, language = {en}, url = {http://www.numdam.org/item/RSMUP_1989__81__49_0/} }