@misc{kur-var-99-elcint,
  author = {A. B. Kurzhanski and P. Varaiya},
  title = {Ellipsoidal Techniques for Reachability Analysis: {Internal} Approximation},
  url = {http://citeseer.nj.nec.com/ps/290581},
  howpublished = {Online document},
  year = 1999,
  month = dec,
  comment = {Computes an elipsoid guaranteed to be inside the reachable set of a differential equation. Apparently assumes ellipsoidal calculus but gives no details on the same.},
  altkeys = {Citeseer:state-ellipsoidal}
}