1. Hashizume, H., A.Kaneko, Y.Sugano, K.Yatani, and M.Sugimoto. 2005. “Fast and Accurate Positioning Technique Using Ultrasonic Phase Accordance Method.” In Proceedings of IEEE region 10 conference (TENCON2005), Melbourne, Australia, 1–6.
2. Broadband ultrasonic location systems for improved indoor positioning
3. Holm, S.2012. “Ultrasound Positioning Based on Time-of-Flight and Signal Strength.” In Proceedings of IEEE IPIN 2012, Sydney, Australia, 1–6.
4. High-Precision Ultrasonic Ranging System Platform Based on Peak-Detected Self-Interference Technique
5. A Scalable Tracking System Using Ultrasonic Communication