TY - JOUR AU - Sharma, Jaita Pankaj AU - George, Raju K. TI - Controllability of matrix second order systems: a trigonometric matrix approach JO - Electronic Journal of Differential Equations PY - 2007 VL - 2007 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/EJDE_2007__2007__a22/ LA - en ID - EJDE_2007__2007__a22 ER -