Perhaps you should try some spelling variations:
chieu tinh » trieu tinh, lieu tinh, chau tinh
hieu quang » thieu quang, hieu quan, hieu qua
trang xay » trang xa, trang va, trinh xay
trong xay » thong xay, trong cac, trong ca
dung cong » dung trong
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
toan tap » toan ban

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: theo ((chieu tinh) or (hieu quang)) - hanh ((trang xay) OR (trong xay)) dung cong dan toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((chieu tinh) OR (hieu quang)) - hanh ((trang xay) OR (trong xay)) dung cong dan toan tap*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((chieu tinh) or (hieu quang)) - hanh ((trang xay) OR (trong xay)) dung cong dan toan tap*".