@inproceedings{Braghin:2007xH,
  author = "Braghin, Fábio",
  title = "{Free Parameters in Quantum Theories: an Analysis with the Variational Approximation }",
  doi = "10.22323/1.031.0021",
  booktitle = "Proceedings of Fifth International Conference on Mathematical Methods in Physics  {\textemdash} PoS(IC2006)",
  year = 2007,
  volume = "031",
  pages = "021"
}