Chriss A. Grosvenor Robert T. Johnk James Baker-Jarvis Michael D. Janezic B. Riddle Time-Domain Free-Field Measurements of the Relative Permittivity of Building Materials. 2275-2282 2009 58 IEEE Trans. Instrum. Meas. 7 https://doi.org/10.1109/TIM.2009.2013916 db/journals/tim/tim58.html#GrosvenorJBJR09