Perhaps you should try some spelling variations:
chieu xanh » chieu sach, chieu tinh, hieu manh
chieu sang » chieu sach, hieu lang, nhieu tang
hanh tranh » canh tranh, hanh trinh, hanh trang
tranh qua » tranh cua, thanh qua, trinh qua
song song » song hong, song dong, xuong song
song van » hoang van, trong van, duong van
van toan » van tuan, van tan, van thanh
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 (chieu sang)) - hanh tranh qua song song van toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu xanh) OR (chieu sang)) - hanh tranh qua song song van toan cau*.