Perhaps you should try some spelling variations:
vien thanh » viet thanh, tien thanh, dien thanh
hieu manh » chieu xanh, hieu nganh, dieu hanh
hang cong » dang cong, hang nong, bang cong
tran van » luan van
cong san » cong tac
san toan » van toan, dan toan, 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 ((hieu manh) or (vien thanh)) - hanh ((tran van) or (hang va)) hang cong san toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu manh) OR (vien thanh)) - hanh ((tran van) OR (hang va)) hang cong san toan cao.
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu manh) or (vien thanh)) - hanh ((tran van) or (hang va)) hang cong san toan cao*.