Perhaps you should try some spelling variations:
hien nhanh » thien thanh, tien thanh, dien thanh
hien hanh » dieu hanh
hanh sinh » hanh tinh, hanh dinh, hinh sinh
dung cong » dung trong
sinh qua » sinh quan, sinh cua, tinh quan
qua dung » quang dung, su dung, qua song
san toan » van toan, manh toan, xuan toan
dan toan » van toan, dan than, manh toan

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hien hanh) OR (hien nhanh)) - hanh sinh qua dung cong ((san toan) OR (dan toan)) cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hien hanh) or (hien nhanh)) - hanh sinh qua dung cong ((san toan) OR (dan toan)) cau~".
• Adding a wildcard symbol may retrieve word variants: hoc ((hien hanh) or (hien nhanh)) - hanh sinh qua dung cong ((san toan) OR (dan toan)) cau*.