Perhaps you should try some spelling variations:
hieu nganh » vien nganh, hiem ngan, hieu manh
doc hieu » toc thieu, hoc thieu, hoc hien
trang va » tran van, hang va
quan van » luan van, quan va, quan luan
cong dan » cong tan, huong dan, cong dong
cong san » cong tac
than cau » toan cau, phan cau, than cap

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 nganh - hanh ((trang va) or (quan van)) nhung ((cong dan) OR (cong san)) than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu nganh - hanh ((trang va) OR (quan van)) nhung ((cong dan) OR (cong san)) than cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu nganh - hanh ((trang va) or (quan van)) nhung ((cong dan) OR (cong san)) than cau*".