1David R. Skinner Speed Control:美国专利,UDP4145161[P],1979-03-20.
2Yanfu Wei, Xiangguang Chen Y , Zhang Min. Research on Oil Extraction Modeling and Optimum Control Method in Oil Field[C]. The 2nd International Conference on Electrical and Control Engineering ( ICECE2011 ), YiChang, China, 2011:792-795.