Perhaps you should try some spelling variations:
hanh trang » thanh trung, canh tranh, hanh trinh
hieu quan » hieu qua, lieu quan, thien quan
lang cong » bang cong, hang cong, lang dong
dang cong » dung cong
nho hieu » nha hieu, nho sieu, nhu hieu
trang va » tran van, hang va
than cau » toan cau, phan cau, than cap

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

• Performing a fuzzy search may retrieve terms with similar spellings: nho hieu quan - hanh trang va ((lang cong) or (dang cong)) dan ((than cau) or (thanh san))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: nho hieu quan - hanh trang va ((lang cong) OR (dang cong)) dan ((than cau) OR (thanh san)).
• Adding a wildcard symbol may retrieve word variants: nho hieu quan - hanh trang va ((lang cong) or (dang cong)) dan ((than cau) or (thanh san))*.