@article{ASENS_1997_4_30_4_417_0, author = {Gordon, Carolyn S. and Mao, Yiping and Schueth, Dorothee}, title = {Symplectic rigidity of geodesic flows on two-step nilmanifolds}, journal = {Annales scientifiques de l'\'Ecole Normale Sup\'erieure}, pages = {417--427}, publisher = {Elsevier}, volume = {Ser. 4, 30}, number = {4}, year = {1997}, doi = {10.1016/s0012-9593(97)89927-2}, zbl = {0897.53033}, mrnumber = {98g:53077}, language = {en}, url = {http://www.numdam.org/articles/10.1016/s0012-9593(97)89927-2/} }