Thickness Distribution of Metal Films by Magnetron Sputtering (II) – Effect of the Distance between the Target and Substrate and the Erosion Distribution – Toshinari Yamazaki, Takayuki Kida, Toshio Yoshizawa, Toshio Kikuta, Takaki Yamamoto J. Vac. Soc. Jpn., 56(9), 382-385 (2013).