00320nam a2200121Ia 4500082001700000100002200017245007000039260002900109300001500138490003500153500000500188700000500193  a516bG958.MM  aGuillemin, Victor  aMoment maps and combinatorial invariants of Hamiltonian T-spaceb  aBostonbBirkhauserc1994  avii, 150p.  aProgress in Mathematics v 122  a  a