1. Ai, X., & Xiao, H. (1988). Cutting with ceramic tool. Beijing: Machine Press. (in Chinese).
2. ANON. (2017). List of countries by vehicles per Capita. [Online]. Wikipedia, The Free Encyclopedia. Available from:
https://en.wikipedia.org/wiki/List_of_countries_by_vehicles_per_capita
. Accessed April 2, 2017.
3. Balamuth, L. (1964). Recent developments in ultrasonic metalworking processes. SAE Technical Paper 640149.
4. Bai, J., Liu, J., et al. (2014). Non-traditional machining (6th ed.). Beijing: Machine Press. (in Chinese).
5. Bourell, D., & Beaman, J. (2012). The history of laser additive manufacturing. [Online] Lasers Today. Available from:
http://www.laserstoday.com/2012/04/the-history-of-laser-additive-manufacturing
. Accessed March 28, 2014.