Perhaps you should try some spelling variations:
thin zheng » chen zheng, qin zheng, things zhang
zheng rong » chen rong
some past » some case, time past
rong ping » dong ping, ting ping
yan yang » yang yang, yao yang, dan yang
tan yang » dan yang, tan ying, tan yong
time pad » time part, time pcr

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: lang ((yan yang) OR (tan yang)) ((time pad) OR (some past)) thin zheng rong ping ;~.
• Adding a wildcard symbol may retrieve word variants: lang ((yan yang) or (tan yang)) ((time pad) or (some past)) thin zheng rong ping ;*.