Perhaps you should try some spelling variations:
hieu xanh » chieu xanh, hieu manh, hieu nganh
doc hieu » toc thieu, hoc thieu, hoc hien
tung hoc » trung hoc, tuong hoc, tung ho
dung hoc » dong hoc, dung thuoc, trung hoc
cong ban » cong bang, cong san, cong dan
cong tan » cong tac, cong san, cong thanh
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 - thanh ((tung hoc) or (dung hoc)) thuong ((cong ban) or (cong tan)) toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu xanh - thanh ((tung hoc) OR (dung hoc)) thuong ((cong ban) OR (cong tan)) toan cau.
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - thanh ((tung hoc) or (dung hoc)) thuong ((cong ban) or (cong tan)) toan cau*.