Perhaps you should try some spelling variations:
chieu xanh » chieu sach, chieu sang, chieu tinh
canh trinh » canh tranh, hanh trinh, canh tinh
nhung cong » dung cong, thong cong, hang cong
hien xanh » hien hanh, hien nhanh, hien khanh
trinh va » trinh van, trinh vat, trinh ve
cong tap » cuong tap, cong tac, cong tan
tap toan » tap doan, tap quan, bai toan
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 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 toan cao.
• Adding a wildcard symbol may retrieve word variants: hoc ((hien xanh) or (chieu xanh)) - canh trinh va nhung cong tap toan cao*.