@article{article3d2fa943,
title   = {Impulsive stability for systems of second order retarded differential equations},
author = {Gimenes, Luciene Parron and Federson, Marcia and Taboas, Placido Zoega},
year = {2007},
doi = {10.1016/j.na.2006.06.006},
journal   = {Nonlinear Analysis : Theory, Methods and Applications}
}