@Article{ 
  GutManMor16,
  author = { Gutt, Jan and Manno, Gianni and Moreno, Giovanni },
  title = { Completely exceptional 2nd order PDEs via conformal geometry and BGG resolution },
  journal = { Journal of Geometry and Physics },
  year = { 2016 },
  doi = { http://dx.doi.org/10.1016/j.geomphys.2016.04.021 },
  pages = {  },
  URL = { https://gecogedi.dimai.unifi.it/paper/8/ },
  note = { cvgmt preprint}
}