Perhaps you should try some spelling variations:
thien quan » trien quang, lien quan, thien van
hieu quan » hieu qua, lieu quan, lien quan
hanh tang » hanh trang, anh tang, hanh mang
nang cong » nang song, dang cong, hang cong
bang cong » dang cong, bang song, hang cong
tan than » tan thanh, tan tran, ban than
than ban » thanh ban, toan ban, than man
tang va » trang va, tang van, thang va

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 (thien quan)) - hanh tang va ((nang cong) OR (bang cong)) tan than ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((hieu quan) OR (thien quan)) - hanh tang va ((nang cong) OR (bang cong)) tan than ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((hieu quan) or (thien quan)) - hanh tang va ((nang cong) OR (bang cong)) tan than ban".
• Adding a wildcard symbol may retrieve word variants: ho ((hieu quan) or (thien quan)) - hanh tang va ((nang cong) OR (bang cong)) tan than ban*.