Perhaps you should try some spelling variations:
chieu tinh » trieu tinh, lieu tinh, chau tinh
chieu sach » chinh sach, chiet tach, chieu sang
nhung cong » dung cong, thong cong, hang cong
hach toan » thanh toan, manh toan
quang ma » xquang ma, quang va, quang manh
ma nhung » va nhung, a nhung, la nhung
tac toan » tap toan, tam toan, tich toan

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 (chieu sach)) - nhanh quang ma nhung cong ((tac toan) OR (hach toan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((chieu tinh) OR (chieu sach)) - nhanh quang ma nhung cong ((tac toan) OR (hach toan)) cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((chieu tinh) or (chieu sach)) - nhanh quang ma nhung cong ((tac toan) OR (hach toan)) cau".
• Adding a wildcard symbol may retrieve word variants: theo ((chieu tinh) or (chieu sach)) - nhanh quang ma nhung cong ((tac toan) OR (hach toan)) cau*.