Perhaps you should try some spelling variations:
hanh trang » thanh trung, hanh trinh, minh trang
hieu quan » hieu qua, lieu quan, thien quan
hang cong » hang nong, bang cong, thanh cong
dang cong » dung cong
dang toan » dang tran, dan toan, dung toan
hoc hieu » hoc thieu, hoc hien, doc hieu
toan ban » van ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hieu quan - ((hanh trang) or (canh tranh)) va ((hang cong) or (dang cong)) dang toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu quan - ((hanh trang) OR (canh tranh)) va ((hang cong) OR (dang cong)) dang toan ban.
• Adding a wildcard symbol may retrieve word variants: hoc hieu quan - ((hanh trang) or (canh tranh)) va ((hang cong) or (dang cong)) dang toan ban*.