@article{GossonGosson2006,
  author    = {Maurice A. de Gosson and Serge M. de Gosson},
  title     = {Extension of the Conley-Zehnder index, a product formula, and an application to the Weyl representation of metaplectic operators},
  journal   = {Journal of mathematical physics},
  volume    = {47},
  number    = {12},
  doi       = {10.1063/1.239066},
  year      = {2006},
}