Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
hien xanh » hien hanh, hien nhanh, chieu xanh
trinh cua » tinh cua, trinh quan, trinh luan
chinh cau » chinh chau, chinh ca, chinh can
cong tan » cong tac, cong san, cong thanh
chan cau » phan cau, can cau, nhanh cau

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

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