TY - JOUR AU - M. Jotz AU - K.-H. Neeb TI - Closedness of the Tangent Spaces to the Orbits of Proper Actions JO - Journal of Lie Theory PY - 2008 SP - 517 EP - 521 VL - 18 IS - 3 UR - http://geodesic.mathdoc.fr/item/JOLT_2008_18_3_a1/ ID - JOLT_2008_18_3_a1 ER -