Perhaps you should try some spelling variations:
chieu sang » chieu sach, chieu xanh, hieu lang
trinh quan » tinh quang, trinh luat, trinh han
hieu manh » chieu xanh, hieu nganh, dieu hanh
trinh cua » tinh cua, trinh luat, trinh luan
hang cong » dang cong, hang nong, bang cong
cong tan » cong tac, cong san, cong thanh
tan van » tran van, tang van, luan van

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) or (chieu sang)) - hanh ((trinh cua) OR (trinh quan)) hang cong tan van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu manh) OR (chieu sang)) - hanh ((trinh cua) OR (trinh quan)) hang cong tan van ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hieu manh) or (chieu sang)) - hanh ((trinh cua) OR (trinh quan)) hang cong tan van ban".
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu manh) or (chieu sang)) - hanh ((trinh cua) OR (trinh quan)) hang cong tan van ban*.