Perhaps you should try some spelling variations:
thiet tach » chiet tach, thien hach, thuat tach
hoc thiet » hoc thieu, hoc thuyet, hoc hien
hanh ban » thanh ban, hang ban, hanh san
cua dung » cua dang, cua dong, qua dung
cong dan » cong san, cong tan, huong dan
dan than » dan chan, ban than, van than
than cau » toan cau, phan cau, than cap

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 thiet tach - hanh ban ((cua dung) OR (cua ban)) cong dan than cau~.
• Adding a wildcard symbol may retrieve word variants: hoc thiet tach - hanh ban ((cua dung) or (cua ban)) cong dan than cau*.