Perhaps you should try some spelling variations:
quang trach » quang thanh, quang tran
hieu quang » thieu quang, hieu quan, hieu qua
dinh quang » tinh quang, minh quang, dinh duong
trach hung » tranh nhung, tran hung, thanh hung
hung cuong » hung vuong, hong cuong, hung luong
hieu sang » chieu sang, hieu lang, nhieu tang
cuong tap » luong tap, cong tac, luong tai
tap van » tap va, tap vat, tap quan

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((hieu sang) or (hieu quang)) - dinh quang trach hung cuong tap van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu sang) OR (hieu quang)) - dinh quang trach hung cuong tap van ban.
• Adding a wildcard symbol may retrieve word variants: doc ((hieu sang) or (hieu quang)) - dinh quang trach hung cuong tap van ban*.