Perhaps you should try some spelling variations:
chiet tach » chieu sach
thong cong » trong cong, tong cong, thong thong
doi chiet » doi chieu, doi chi, doi viet
trinh vit » trinh viet, trinh vat, trinh vuot
trinh vi » trinh va, trinh ve, trinh viet
cong tan » cong tac, cong san, cong thanh
tan phan » toan phan, than phan, van phan

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi chiet tach - canh ((trinh vi) or (trinh vit)) thong cong tan phan tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi chiet tach - canh ((trinh vi) OR (trinh vit)) thong cong tan phan tu.
• Adding a wildcard symbol may retrieve word variants: doi chiet tach - canh ((trinh vi) or (trinh vit)) thong cong tan phan tu*.