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