Perhaps you should try some spelling variations:
thiet tach » chiet tach, thien hach, thuat tach
hoc thiet » hoc thieu, hoc thuyet, hoc hien
hanh tran » hanh trang, thanh tran, hanh tram
dung cong » dung trong
tran van » luan van
van dung » van dong, xay dung, tin dung
cong tan » cong tac, cong san, cong thanh
than cap » khan cap, thanh lap, thanh cac
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 tran van dung cong tan ((than cap) OR (phan cau))~.
• Adding a wildcard symbol may retrieve word variants: hoc thiet tach - hanh tran van dung cong tan ((than cap) or (phan cau))*.