Perhaps you should try some spelling variations:
thong cong » trong cong, tong cong, thong thong
chiet tach » chieu sach
doi chiet » doi chieu, doi chi, doi viet
trinh vat » trinh van, trinh luat, sinh vat
tranh va » tranh van, trang va, trinh va
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 ((tranh va) or (trinh vat)) thong cong tan phan tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi chiet tach - canh ((tranh va) OR (trinh vat)) thong cong tan phan tu.
• Adding a wildcard symbol may retrieve word variants: doi chiet tach - canh ((tranh va) or (trinh vat)) thong cong tan phan tu*.