Title: Hyperbolicity of Hamiltonian systems of negative curvature
Authors: A.A. Agrachëv, N.N. Shcherbakova
Journal title: Dokl. Akad. Nauk
Year: 2005
Issue: 3
Volume: 400
Pages: 295–298
MathNet (ENG):
http://mi.mathnet.ru/eng/dan1316