Perhaps you should try some spelling variations:
canh trinh » canh tranh, hanh trinh, canh tinh
chieu xanh » chieu sach, chieu sang, chieu tinh
trinh quan » tinh quang, trinh luat, trinh han
hieu manh » hieu nganh, dieu hanh, hien hanh
tong cong » trong cong, cong cong, dung cong
hang cong » dang cong, hang nong, bang cong
tap toan » tap doan, tap quan, bai toan
toan cau » 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 ((chieu xanh) or (hieu manh)) - canh trinh quan ((tong cong) or (hang cong)) tap toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu xanh) OR (hieu manh)) - canh trinh quan ((tong cong) OR (hang cong)) tap toan cau.
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu xanh) or (hieu manh)) - canh trinh quan ((tong cong) or (hang cong)) tap toan cau*.