Perhaps you should try some spelling variations:
chieu sang » chieu sach, hieu lang, nhieu tang
chieu xanh » chieu sach, chieu tinh, hieu manh
hanh trung » thanh trung, hanh trang, manh trung
nhung cong » dung cong, thong cong, hang cong
trung va » truong va, trang va, trung ha
cong tac » cong ty
tac toan » tap toan, tam toan, hach 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 sang) or (chieu xanh)) - hanh trung va nhung cong tac toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu sang) OR (chieu xanh)) - hanh trung va nhung cong tac toan cau.
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sang) or (chieu xanh)) - hanh trung va nhung cong tac toan cau*.