Differential Equations & Applications · Volume 3, Issue 3 Indirect locally internal observability and controllability of weakly coupled wave equations 03-28 Pages 449-462 DOI 10.7153/dea-03-28 Downloads Short PDF Full PDF PNG Authors Ali Wehbe Wael Youssef Keywords wave equation coupled system indirect observability indirect exact controllability Subject classes 35B37 35D05 73K50 93C20