%0 Journal Article %A Levy, Jason %T Rationality and Orbit Closures %J Canadian mathematical bulletin %D 2003 %P 204-215 %V 46 %N 2 %U http://geodesic.mathdoc.fr/articles/10.4153/CMB-2003-021-6/ %R 10.4153/CMB-2003-021-6 %F 10_4153_CMB_2003_021_6