Perhaps you should try some spelling variations:
hieu cach » hieu cac, chieu sach, hieu ca
dung cong » dung trong
hoc hieu » hoc thieu, hoc hien, doc hieu
trung va » truong va, trang va, trung ha
tran van » luan van
cong dan » cong san, cong tan, huong dan
toan cau » toan cao, toan ban, toan tap
than cap » khan cap, thanh lap, thanh cac

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 hieu cach - thanh ((trung va) OR (tran van)) dung cong dan ((toan cau) OR (than cap))~.
• Adding a wildcard symbol may retrieve word variants: hoc hieu cach - thanh ((trung va) or (tran van)) dung cong dan ((toan cau) or (than cap))*.