@book{Lamport,
  title     = "\LaTeX: A Document Preparation
              System",
  author    = "Lamport, Leslie",
  publisher = "Addison-Wesley",
  year      = 1994
}

@book{Companion,
  title     = "\LaTeX{} Companion",
  author    = "Goossens, Michel and Mittelbach,
              Frank and Samarin, Alexander",
  publisher = "Addison-Wesley",
  year      = 1994
}