@PhdThesis{herraiz2008:evolution_properties,
  author    = 	 {Israel Herraiz},
  title     = 	 {A statistical examination of the evolution and properties of libre software},
  school    = 	 {Universidad Rey Juan Carlos},
  year      = 	 {2008},
  note      = 	 {http://purl.org/net/who/iht/phd},
}