@Article{ 
  colsabstr02,
  author = { Colombo, Fabrizio and Frank, Sommen and Sabadini, Irene and Struppa, Daniele },
  title = { Syzygies and conservation laws },
  journal = { Foundations of Physics Letters },
  year = { 2002 },
  volume = { 15 },
  pages = { 507-522 },
  URL = { http://cvgmt.sns.it/paper/938/ },
  note = { cvgmt preprint}
}