Perhaps you should try some spelling variations:
manh trong » manh truong, anh trong, manh trung
chieu sang » chieu sach, chieu xanh, nhieu tang
nhung cong » dung cong, thong cong, nhung don
hieu lang » hieu quang, nhieu tang, hieu van
hang cong » dang cong, hang nong, bang cong
tac luan » tac quan, tao 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: doi ((chieu sang) OR (hieu lang)) - manh trong nganh ((nhung cong) or (hang cong)) tac luan van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi ((chieu sang) OR (hieu lang)) - manh trong nganh ((nhung cong) OR (hang cong)) tac luan van.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi ((chieu sang) OR (hieu lang)) - manh trong nganh ((nhung cong) or (hang cong)) tac luan van".
• Adding a wildcard symbol may retrieve word variants: doi ((chieu sang) OR (hieu lang)) - manh trong nganh ((nhung cong) or (hang cong)) tac luan van*.