@BOOK{aschur,
  author     = {Hans Brox and Wolf-Dietrich Walker},
  title      = {Allgemeines Schuldrecht},
  language   = {ngerman},
  edition    = {29.},
  year       = 2003,
  address    = {M\"unchen}}

@BOOK{bschur,
  author     = {Hans Brox and Wolf-Dietrich Walker},
  title      = {Besonderes Schuldrecht},
  shorttitle = {BSchuR},
  language   = {ngerman},
  edition    = {27.},
  year       = 2002,
  address    = {M\"unchen}}