Journal of Geometry and Physics
Journal of Geometry and Physics > 2002 > 42 > 4 > 296-306
Journal of Geometry and Physics > 2002 > 44 > 2-3 > 129-155
Journal of Geometry and Physics > 2002 > 42 > 4 > 296-306
Journal of Geometry and Physics > 2002 > 44 > 2-3 > 129-155