Perhaps you should try some spelling variations:
chieu xanh » chieu sach, chieu sang, chieu tinh
canh trinh » canh tranh, hanh trinh, canh tinh
hien xanh » hien hanh, hien nhanh, hien khanh
cuong tap » luong tap, cong tac, luong tai
trinh va » trinh van, trinh vat, trinh ve
cong tap » cong tac, cong tan, tong tap
toan cao » toan ban, toan tap

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