@InProceedings{	  bowlcalib2007,
  author	= "Pietro Cerri AND Oscar Gerelli AND Dario {Lodi Rizzini}",
  title		= "{Bowling for Calibration: an Undemanding Camera
		  Calibration Procedure using a Sphere}",
  booktitle	= "Intl.~Wks.~on Camera Calibration Methods for Computer
		  Vision Systems",
  month		= mar,
  eprint	= "doi:10.2390/biecoll-icvs2007-166",
  year		= "2007"
}