Perhaps you should try some spelling variations:
quang tong » quang thong, quang dong, quang tung
hieu sang » chieu sang, hieu quang, nhieu tang
hieu lang » chieu sang, hieu quang, nhieu tang
hanh luan » khanh luan, hang luan, hanh luat
van quang » van quan, tran quang, van tuan
tong minh » thong minh, trong minh, song minh
minh toan » tinh toan, manh toan, minh tuan
toan cau » toan cao, toan ban, toan tap

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 lang)) - hanh luan van quang tong minh toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu sang) OR (hieu lang)) - hanh luan van quang tong minh toan cau.
• Adding a wildcard symbol may retrieve word variants: doc ((hieu sang) or (hieu lang)) - hanh luan van quang tong minh toan cau*.