Perhaps you should try some spelling variations:
hieu quan » hieu qua, thien quan, lien quan
lieu quan » lien quan, hieu qua, lieu van
nang cong » nang song, dang cong, bang cong
thang va » hang va, trang va, thong va
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
toan ban » van ban
tang va » trang va, tang van, tang vat

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((hieu quan) or (lieu quan)) - hanh ((tang va) OR (thang va)) nang cong dan toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((hieu quan) OR (lieu quan)) - hanh ((tang va) OR (thang va)) nang cong dan toan ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((hieu quan) or (lieu quan)) - hanh ((tang va) OR (thang va)) nang cong dan toan ban".
• Adding a wildcard symbol may retrieve word variants: ho ((hieu quan) or (lieu quan)) - hanh ((tang va) OR (thang va)) nang cong dan toan ban*.