@inproceedings{Langer1995, author = "Michael Langer and Gregory Dudek and Steven W. Zucker", address = "Pittsburgh, PA", year = "1995", month = "August", publisher = "IEEE Press", booktitle = "Proceedings IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)", pages = "390-396", title = "Space occupancy using multiple shadowimages", refnumber = "3 conference paper" }