Perhaps you should try some spelling variations:
hien xanh » hien hanh, hien nhanh, chieu xanh
dung cong » dung trong
trung ha » trung hoc, trung tam, trung cap
trang va » tran van, hang va
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
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: hoc hien xanh - hanh ((trung ha) or (trang va)) dung cong dan toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hien xanh - hanh ((trung ha) OR (trang va)) dung cong dan toan cau.
• Adding a wildcard symbol may retrieve word variants: hoc hien xanh - hanh ((trung ha) or (trang va)) dung cong dan toan cau*.