Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
nhung cong » dung cong, thong cong, hang cong
truong va » truong dai, truong cao, truong dao
hoc hieu » hoc thieu, hoc hien, doc hieu
tuong va » thuong va, luong va, duong va
tan luan » tang luan, toan luan, san luan
dan luan » doanh luan, dung luan, tang luan

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 - manh ((tuong va) OR (truong va)) nhung cong ((tan luan) or (dan luan)) van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu quang - manh ((tuong va) OR (truong va)) nhung cong ((tan luan) OR (dan luan)) van.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hieu quang - manh ((tuong va) OR (truong va)) nhung cong ((tan luan) or (dan luan)) van".
• Adding a wildcard symbol may retrieve word variants: hoc hieu quang - manh ((tuong va) OR (truong va)) nhung cong ((tan luan) or (dan luan)) van*.