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
trong san » trong cac, cong san, dong san
sinh qua » sinh quan, sinh cua, tinh quan
qua dung » quang dung, su dung, qua song
san toan » van toan, dan toan, manh toan
toan cau » toan cao, toan ban, toan tap

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 trong san toan cau~.
• Adding a wildcard symbol may retrieve word variants: hoc ((hien hanh) or (hien nhanh)) - hanh sinh qua dung trong san toan cau*.