Perhaps you should try some spelling variations:
chieu tinh » trieu tinh, lieu tinh, chau tinh
hieu quang » thieu quang, hieu quan, hieu qua
hanh tran » hanh trang, thanh tran, hanh tram
tong cong » trong cong, cong cong, dang cong
dung cong » dung trong
tran han » tran hanh, tran hoan, tran nhan
dan toan » van toan, dan than, manh 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 (hieu quang)) - hanh tran han ((tong cong) or (dung cong)) dan toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chieu tinh) OR (hieu quang)) - hanh tran han ((tong cong) OR (dung cong)) dan toan cau.
• Adding a wildcard symbol may retrieve word variants: ho ((chieu tinh) or (hieu quang)) - hanh tran han ((tong cong) or (dung cong)) dan toan cau*.