Perhaps you should try some spelling variations:
hieu manh » chieu xanh, hieu nganh, dieu hanh
hang cong » dang cong, hang nong, bang cong
hoc hieu » hoc thieu, hoc hien, doc hieu
tinh cua » trinh cua, sinh cua, tinh chat
cong tan » cong tac, cong san, cong thanh
phan cau » phan cac, phan tu, phan lap
phan dau » phan tu, hang dau
luat » luan, xuat

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hieu manh - hanh ((trinh luat) or (tinh cua)) hang cong tan ((phan cau) OR (phan dau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu manh - hanh ((trinh luat) OR (tinh cua)) hang cong tan ((phan cau) OR (phan dau)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hieu manh - hanh ((trinh luat) or (tinh cua)) hang cong tan ((phan cau) OR (phan dau))".
• Adding a wildcard symbol may retrieve word variants: hoc hieu manh - hanh ((trinh luat) or (tinh cua)) hang cong tan ((phan cau) OR (phan dau))*.