1. (1) Wireless Microphone System [Online]. Available at http://www.jstage.jst.go.jp/article/ieiej/31/11/31_858/_pdf
2. (2) Digital Signal Processing in RF Applications [Online]. Available at http://cas.web.cern.ch/cas/Sweden2007/Lectures/Web-versions/Schilcher-1.pdf
3. (3) H. Nishikawa, A. Yoshimi. K. Takemura, A. Tanaka, and T. Douseki : “Batteryless wireless transmission system for electric drum uses piezoelectric generator for play signal and power source”, Power MEMS 2015, Journal of Physics: Conference Series 660(2015)012100, pp. 1-5 (2015)
4. (4) K. Takemura, A. Yoshimi, H. Nishikawa, A. Tanaka, and T. Douseki : “Batteryless 900-us-Latency FM Transmitter Powered by Piezoelectric Generator for Wireless Electronic Drum”, Proceedings of IEEE SENSORS 2015 Conference, pp. 1413-1416 (2015)
5. (6) Electronic Drums [Online]. Available at http://wc.theclarkwebsite.com/piezos.php