Perhaps you should try some spelling variations:
pumping control » pacing control, comparing control, computing control
using control » losing control, dosing control, taking control
chang chuan » chung chuan, chen chuan, chang ch'un
qian wang » yiqian wang, qian rong, yan wang
han chang » huang chang, than change, can change
qian yan » qian jun, qian yi

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: wang ((qian wang) OR (qian yan)) han chang chuan ((using control) OR (pumping control)) bi ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "wang ((qian wang) OR (qian yan)) han chang chuan ((using control) or (pumping control)) bi ;~".
• Adding a wildcard symbol may retrieve word variants: wang ((qian wang) OR (qian yan)) han chang chuan ((using control) or (pumping control)) bi ;*.