Perhaps you should try some spelling variations:
dung cong » dung trong
tranh su » trinh su, trang su, tranh cua
cong dan » cong san, cong tan, huong dan
than cau » toan cau, than cap, thanh chau
phan cau » phan dau, phan cac, phan tu
doi chi » doi khi
chi anh » chi danh, chi hanh, thi anh

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi chi anh - canh tranh su dung cong dan ((than cau) or (phan cau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi chi anh - canh tranh su dung cong dan ((than cau) OR (phan cau)).
• Adding a wildcard symbol may retrieve word variants: doi chi anh - canh tranh su dung cong dan ((than cau) or (phan cau))*.