@ARTICLE{maps1,
  AUTHOR	    = {John Doe},
  YEAR		    = {1995}
}

@ARTICLE{maps2,
  AUTHOR	    = {Bill Bran},
  YEAR		    = {1996}
}

@COLLECTION{maps3,
  AUTHOR	    = {Marvin Map},
  YEAR		    = {1945}
}

@BOOK{maps4,
  AUTHOR	    = {Alan Allele},
  YEAR		    = {1995}
}
