@INPROCEEDINGS{ist:montenbruck16d,
  author = {Montenbruck, J. M. and Allg{\"o}wer, F.},
  title = {Persistence of Excitation and the Feedback Theorem for Passive Systems},
  booktitle = {Proc.\ 10th IFAC Symp.\ Nonlinear Control Systems (NOLCOS)},
  year = {2016},
  pubtype = {proceeding}
}