Perhaps you should try some spelling variations:
chiet tach » chieu sach
khong cong » thong cong, khong cang, chong cong
doi chiet » doi chieu, doi chi, doi viet
tranh cua » doanh cua, manh cua
cua khong » hua khong, cua phuong, cua thuong
van tuan » van quan, van ban, anh tuan
bai toan » bai tap

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 cua khong cong ((van tuan) or (bai toan)) ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi chiet tach - canh tranh cua khong cong ((van tuan) OR (bai toan)) ban*.