1. Ultrasonic atomization technology provided by Sono-Tek.
2. Berger, H. L. , Dr. , Ultrasonic Liquid Atomization.
3. Figure 2, Chart from http://www.platinum.matthey.com/pgm-prices/price-charts/
4. Figure 3(a), http://getcheminfo.wikispaces.com/file/view/LipidBilayer1.jpg/95877804/LipidBilayer1.jpg
5. Rayleigh, 1898, Theory of Sound (Dover, NY 1945), p 82, 349.