Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
hieu tinh » chieu tinh, lieu tinh, kieu tinh
doc hieu » toc thieu, hoc thieu, hoc hien
trang va » hang va
tran van » luan van
cong tan » cong tac, cong san, cong thanh
than cau » toan cau, phan cau, than cap
phan cac » nhan cach, phan dau, phan lap

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: doc hieu tinh - hanh ((trang va) or (tran van)) nhung cong tan ((than cau) or (phan cac))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu tinh - hanh ((trang va) OR (tran van)) nhung cong tan ((than cau) OR (phan cac)).
• Adding a wildcard symbol may retrieve word variants: doc hieu tinh - hanh ((trang va) or (tran van)) nhung cong tan ((than cau) or (phan cac))*.