Perhaps you should try some spelling variations:
thanh trung » thanh tung
hieu quan » hieu qua, lieu quan, thien quan
bang cong » dang cong, bang song, hang cong
cong lang » cong vang, cong luong, cong quang
lang toan » dang toan, lang thang, lang thanh
hoc hieu » hoc thieu, hoc hien, doc hieu
toan ban » van ban
va bang » va nang, va lang, va 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 - ((thanh trung) or (canh tranh)) va bang cong lang toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu quan - ((thanh trung) OR (canh tranh)) va bang cong lang toan ban.
• Adding a wildcard symbol may retrieve word variants: hoc hieu quan - ((thanh trung) or (canh tranh)) va bang cong lang toan ban*.