Journal of Geometry and Physics
Journal of Geometry and Physics > 2002 > 43 > 4 > 293-309
Journal of Geometry and Physics > 2002 > 43 > 4 > 310-326
Journal of Geometry and Physics > 2002 > 43 > 4 > 293-309
Journal of Geometry and Physics > 2002 > 43 > 4 > 310-326