Perhaps you should try some spelling variations:
chieu tinh » trieu tinh, lieu tinh, chau tinh
chieu sang » chieu sach, chieu xanh, hieu lang
hanh trinh » canh tranh, hanh chinh
trinh vat » trinh van, trinh luat, sinh vat
dung cong » dung trong
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: ho ((chieu tinh) or (chieu sang)) - hanh trinh vat ((dung cong) or (han tong)) tap toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chieu tinh) OR (chieu sang)) - hanh trinh vat ((dung cong) OR (han tong)) tap toan cau.
• Adding a wildcard symbol may retrieve word variants: ho ((chieu tinh) or (chieu sang)) - hanh trinh vat ((dung cong) or (han tong)) tap toan cau*.