Perhaps you should try some spelling variations:
cong thanh » dong thanh, cong trinh, cong tan
hieu xanh » chieu xanh, hieu manh, hieu nganh
hanh tang » hanh trang, anh tang, hanh mang
doc hieu » toc thieu, hoc thieu, hoc hien
va thong » va thuong, va phuong, he thong
cong san » cong tac
toan cau » toan cao, toan tap, toan tai
toan ban » van ban
tang va » trang va, tang van, thang va

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 va thong ((cong thanh) or (cong san)) ((toan cau) or (toan ban))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu xanh - hanh tang va thong ((cong thanh) OR (cong san)) ((toan cau) OR (toan ban)).
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - hanh tang va thong ((cong thanh) or (cong san)) ((toan cau) or (toan ban))*.