Perhaps you should try some spelling variations:
cong thanh » dong thanh, truong thanh
hien xanh » hien hanh, hien nhanh, chieu xanh
cua thong » cua thuong, cua khong, cua tong
anh tang » anh bang, anh dang, anh nang
tang cua » mang cua, hang cua, tang luan
cong tan » cong tac, cong san, cong ty
toan tap » toan ban

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 - anh tang cua thong ((cong tan) or (((cong thanh) OR (cong trinh)))) toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hien xanh - anh tang cua thong ((cong tan) OR (((cong thanh) OR (cong trinh)))) toan tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hien xanh - anh tang cua thong ((cong tan) or (((cong thanh) OR (cong trinh)))) toan tap".
• Adding a wildcard symbol may retrieve word variants: hoc hien xanh - anh tang cua thong ((cong tan) or (((cong thanh) OR (cong trinh)))) toan tap*.