Perhaps you should try some spelling variations:
cong thanh » dong thanh, cong trinh, cong tan
hanh tang » hanh trang, anh tang, hanh mang
cua nhung » va nhung
doc hieu » hoc thieu, hoc hien
tang cua » mang cua, hang cua, tang luan
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) OR (toc thieu)) xanh - hanh tang cua nhung ((cong dan) or (cong thanh)) toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc hieu) OR (toc thieu)) xanh - hanh tang cua nhung ((cong dan) OR (cong thanh)) toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doc hieu) OR (toc thieu)) xanh - hanh tang cua nhung ((cong dan) or (cong thanh)) toan cau".
• Adding a wildcard symbol may retrieve word variants: ((doc hieu) OR (toc thieu)) xanh - hanh tang cua nhung ((cong dan) or (cong thanh)) toan cau*.