Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
hieu xanh » chieu xanh, hieu manh, hieu nganh
trinh vat » trinh luat, sinh vat, trinh han
trinh van » trinh han, trinh quan, trinh toan
doc hieu » toc thieu, hoc thieu, hoc hien
cong dan » cong san, cong tan, huong dan
phan cau » phan dau, phan cac, phan tu
hang dau » hang va, hang tai

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 xanh - canh ((trinh vat) OR (trinh van)) nhung cong dan ((phan cau) or (hang dau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu xanh - canh ((trinh vat) OR (trinh van)) nhung cong dan ((phan cau) OR (hang dau)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu xanh - canh ((trinh vat) OR (trinh van)) nhung cong dan ((phan cau) or (hang dau))".
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - canh ((trinh vat) OR (trinh van)) nhung cong dan ((phan cau) or (hang dau))*.