Perhaps you should try some spelling variations:
trong trang » trong tieng, trong tan, hong trang
chieu sach » chinh sach, chiet tach, chieu sang
trong tang » trong tan, trong dang, trong tieng
nhung cong » dung cong, thong cong, hang cong
hieu lang » chieu sang, hieu quang, nhieu tang
cong tac » cong ty
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 sach) or (hieu lang)) - manh ((trong trang) OR (trong tang)) nhung cong tac luan van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi ((chieu sach) OR (hieu lang)) - manh ((trong trang) OR (trong tang)) nhung cong tac luan van.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi ((chieu sach) or (hieu lang)) - manh ((trong trang) OR (trong tang)) nhung cong tac luan van".
• Adding a wildcard symbol may retrieve word variants: doi ((chieu sach) or (hieu lang)) - manh ((trong trang) OR (trong tang)) nhung cong tac luan van*.