@article{ASENS_2000_4_33_2_181_0,
     author = {Gornet, Ruth and Mast, Maura B.},
     title = {The length spectrum of riemannian two-step nilmanifolds},
     journal = {Annales scientifiques de l'\'Ecole Normale Sup\'erieure},
     pages = {181--209},
     publisher = {Elsevier},
     volume = {Ser. 4, 33},
     number = {2},
     year = {2000},
     doi = {10.1016/s0012-9593(00)00111-7},
     mrnumber = {2001d:58042},
     zbl = {0968.53036},
     language = {en},
     url = {http://archive.numdam.org/articles/10.1016/s0012-9593(00)00111-7/}
}