S. Abe, "Social benefits of communication technologies for aging population - a case study of Japan," Asia Culture Forum 2006, Asian Youth Culture Camp Doing Cultural Spaces in Asia, 2006.
J. Alihanka, K. Vaahtoranta, and I. Saarikivi, "A new method for long-term monitoring of the ballistocardiogram, heart rate, and respiration," Am. J. Physiol., vol. n240, 1981.