The HiBall Tracker: high-performance wide-area tracking for virtual and augmented environments. - Greg Welch; Gary Bishop; Leandra Vicci; Stephen Brumback; Kurtis Keller; D'nardo Colucci (VRST, 1999)

High-Performance Wide-Area Optical Tracking: The HiBall Tracking System. - Greg Welch; Gary Bishop; Leandra Vicci; Stephen Brumback; Kurtis Keller; D'nardo Colucci (Presence Teleoperators Virtual Environ., 2001)