Journal of Geometry and Physics
Journal of Geometry and Physics > 1996 > 20 > 4 > 349-370
Journal of Geometry and Physics > 1996 > 20 > 4 > 305-317
Journal of Geometry and Physics > 1996 > 20 > 4 > 349-370
Journal of Geometry and Physics > 1996 > 20 > 4 > 305-317