Perhaps you should try some spelling variations:
dang thanh » dong thanh, dang hanh, hoang thanh
nhung cong » dung cong, thong cong, nhung don
hieu tinh » chieu tinh, lieu tinh, kieu tinh
tranh cua » doanh cua, manh cua
hang cong » dang cong, hang nong, thanh cong
bang cong » dang cong, bang song, dung cong
doc hieu » toc thieu, hoc thieu, hoc hien

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc hieu tinh - canh tranh cua ((nhung cong) or (((hang cong) OR (bang cong)))) dang thanh san~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu tinh - canh tranh cua ((nhung cong) OR (((hang cong) OR (bang cong)))) dang thanh san.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu tinh - canh tranh cua ((nhung cong) or (((hang cong) OR (bang cong)))) dang thanh san".
• Adding a wildcard symbol may retrieve word variants: doc hieu tinh - canh tranh cua ((nhung cong) or (((hang cong) OR (bang cong)))) dang thanh san*.