Perhaps you should try some spelling variations:
cheng zhang » cheng han, zhen zhang, china zhang
phuong thin » phuong thi
chen zheng » chen zhen, chen aizheng, chen zhe
liang wei » xiang wei, zhang wei, wang wei
ha phuong » ha huong, pham phuong, thi phuong
wang yao » wang yan, yang yao, gang yao

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

• Performing a fuzzy search may retrieve terms with similar spellings: wang yao (((zhen OR shen) wei) or (liang wei)) ((cheng zhang) or (chen zheng)) ha phuong thin ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: wang yao (((zhen OR shen) wei) OR (liang wei)) ((cheng zhang) OR (chen zheng)) ha phuong thin ;*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "wang yao (((zhen OR shen) wei) or (liang wei)) ((cheng zhang) or (chen zheng)) ha phuong thin ;*".