Perhaps you should try some spelling variations:
tieng trung » truong trung
chieu sach » chinh sach, chieu sang, chieu xanh
manh trong » manh truong, anh trong, manh trung
trung cong » truong cong, trong cong, trung uong
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 (chiet tach))) or (hieu lang)) - manh trong tieng trung cong tac luan van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi ((((chieu sach) OR (chiet tach))) OR (hieu lang)) - manh trong tieng trung cong tac luan van.
• Adding a wildcard symbol may retrieve word variants: doi ((((chieu sach) or (chiet tach))) or (hieu lang)) - manh trong tieng trung cong tac luan van*.