@ARTICLE{ist:muller.ma15a, author = {M{\"u}ller, M. A. and Liberzon, D. and Allg{\"o}wer, F.}, title = {Norm-controllability of nonlinear systems}, journal = {IEEE Trans.\ Automat.\ Control}, year = {2015}, volume = {60}, pages = {1825-1840}, number = {7} }