Perhaps you should try some spelling variations:
thinh luan » trinh luan, chinh luan, trinh luat
hieu lang » chieu sang, hieu quang, nhieu tang
dang cong » dung cong
cong than » cong thanh, cong thang, cong tan
toc hieu » toc thieu, doc hieu, hoc thieu
van dang » van dong, van dung, van nang
phan dau » phan tu, hang dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc hieu lang - thinh luan van dang cong than ((phan dau) OR (phan lap))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc hieu lang - thinh luan van dang cong than ((phan dau) OR (phan lap))*".