Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
manh tuong » manh tung, manh cuong, minh tuong
hieu sang » chieu sang, hieu lang, nhieu tang
tuong cua » truong cua, huong cua, thong cua
cua trong » cua truong, cua trung, qua trong
cong danh » cuong danh, cong dan, cong thanh
toan tap » toan ban
toan cao » toan ban

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

• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu sang) OR (hieu quang)) - manh tuong cua trong cong danh ((toan tap) OR (toan cao))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu sang) OR (hieu quang)) - manh tuong cua trong cong danh ((toan tap) or (toan cao))~".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu sang) OR (hieu quang)) - manh tuong cua trong cong danh ((toan tap) or (toan cao))*.