Perhaps you should try some spelling variations:
canh trinh » canh tranh, hanh trinh, canh tinh
chieu xanh » chieu sach, chieu sang, chieu tinh
thien anh » thien danh, tien anh, thien thanh
hang cong » hang nong, bang cong, thanh cong
dang cong » dung cong
trinh va » trinh van, trinh vat, trinh ve
dan toan » van toan, dan than, manh 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 ((thien anh) or (chieu xanh)) - canh trinh va ((hang cong) or (dang cong)) dan toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thien anh) OR (chieu xanh)) - canh trinh va ((hang cong) OR (dang cong)) dan toan cao.
• Adding a wildcard symbol may retrieve word variants: hoc ((thien anh) or (chieu xanh)) - canh trinh va ((hang cong) or (dang cong)) dan toan cao*.