@misc{indiciae52aa3f584a9b,
  title = {A torus bifurcation theorem with symmetry},
  author = {Vangils, S. A. and Golubitsky, M.},
  year = {1989},
  url = {https://ntrs.nasa.gov/citations/19890019764},
  note = {Source identifier: 19890019764}
}