Perhaps you should try some spelling variations:
nhung huong » nhung phuong, nhung tuong, nhung cong
hieu quang » thieu quang, hieu qua, diep quang
hieu quan » hieu qua, lieu quan, thien quan
huong lan » phuong lan, thuong lan, huong dan
trang va » hang va
tran van » luan van
lan than » ban than, van than, dan than
than cap » khan cap, thanh lap, thanh cac

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 quang) OR (hieu quan)) - thanh ((trang va) or (tran van)) nhung huong lan than cap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu quang) OR (hieu quan)) - thanh ((trang va) OR (tran van)) nhung huong lan than cap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hieu quang) OR (hieu quan)) - thanh ((trang va) or (tran van)) nhung huong lan than cap".
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu quang) OR (hieu quan)) - thanh ((trang va) or (tran van)) nhung huong lan than cap*.