Free Download A tour of subriemannian geometries, their geodesic… By Richard Montgomery Publisher American Mathematical Society 2002 ISBN 0-8218-4165-3,9780821841655,0-8218-1391-9..

Free Download Points and curves in the Monster tower… By Richard Montgomery, Michail Zhitomirskii Publisher Amer Mathematical Society 2010 ISBN 0821848186,978-0-8218-4818-0,105-106-109-1..