H. J. Hall, D.E. Walker, L. Wang, R.C. Fitch, J.S. Bunch, S. Pourkamali, and V.M. Bright, “Mode Selection Behavior of VHF Thermal-Piezoresistive Self-Sustained Oscillators,” International Conference on Solid State Sensors, Actuators, and Microsystems (Transducers), 2013.