Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
manh tuong » manh tung, manh cuong, minh tuong
nhung cong » dung cong, thong cong, hang cong
doc hieu » toc thieu, hoc thieu, hoc hien
tuong va » truong va, thuong va, luong 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: doc hieu quang - manh tuong va nhung cong ((tan luan) or (dan luan)) van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu quang - manh tuong va nhung cong ((tan luan) OR (dan luan)) van.
• Adding a wildcard symbol may retrieve word variants: doc hieu quang - manh tuong va nhung cong ((tan luan) or (dan luan)) van*.