Perhaps you should try some spelling variations:
danh quang » doanh quang, dang quang, dinh quang
quang hoc » quang hoi, quang huy, dung hoc
dung lam » dung luan, dung tai, dung dat
vat hieu » vat lieu, van hieu, va hieu
hoc viet » hoc hien
viet dat » viec dat, viet da, viet dao
lam vat » lam dat, lam mat, lam chat
hieu so » thieu so
tin » tinh

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tin dung lam vat hieu so ) or ( minh danh quang hoc viet dat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tin dung lam vat hieu so ) OR ( minh danh quang hoc viet dat )).
• Adding a wildcard symbol may retrieve word variants: (( tin dung lam vat hieu so ) or ( minh danh quang hoc viet dat ))*.