@misc{gfp_group_u_2,
  author = {{Groups for Physics}},
  title = {U(2)},
  howpublished = {Groups for Physics reference},
  url = {https://groups.qft.org/atlas/groups/u-2/},
  version = {2026.11-workbench.4},
  note = {Research workbench IV; review status recorded on canonical page}
}