ZHENG Xinqian，YANG Mingyang，ZHANG Yangjun，BAMBA Takahiro，TAMAKI Hideaki，LIN Yun; Asymmetrical Self-Circulating Casing Of Centrifugal Compressor with Circular Sinusoidal Grooves Width，2011.6.15-2031.6.15 ，Chinese Patent， ZL 201010110286.0。