Perhaps you should try some spelling variations:
cong thanh » dong thanh, cong trinh, cong tan
hieu xanh » chieu xanh, hieu manh, hieu nganh
doc hieu » toc thieu, hoc thieu, hoc hien
tang cua » mang cua, tang luan, thong cua
hang cua » mang cua, hang ca, huong cua
cong dan » cong san, cong tan, huong dan
toan cau » toan cao, toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc hieu xanh - hanh ((tang cua) OR (hang cua)) nhung ((cong dan) or (cong thanh)) toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu xanh - hanh ((tang cua) OR (hang cua)) nhung ((cong dan) OR (cong thanh)) toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu xanh - hanh ((tang cua) OR (hang cua)) nhung ((cong dan) or (cong thanh)) toan cau".
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - hanh ((tang cua) OR (hang cua)) nhung ((cong dan) or (cong thanh)) toan cau*.