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
than cau » toan cau, than cap, thanh chau
phan cau » phan dau, phan cac, phan tu

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) OR (phan cau))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thiet tach - hanh ban ((cua dung) or (cua ban)) cong dan ((than cau) OR (phan cau))~".
• Adding a wildcard symbol may retrieve word variants: hoc thiet tach - hanh ban ((cua dung) or (cua ban)) cong dan ((than cau) OR (phan cau))*.