Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
hanh tinh » hanh trinh, nhanh tinh, thanh tinh
bang cong » dang cong, bang song, hang cong
chi sach » chinh sach, chieu sach, co sach
toan cao » toan ban
toan tap » toan ban
doi chi » doi khi

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 sach - hanh tinh chat ((nhung cong) or (bang cong)) dan ((toan cao) or (toan tap))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi chi sach - hanh tinh chat ((nhung cong) OR (bang cong)) dan ((toan cao) OR (toan tap)).
• Adding a wildcard symbol may retrieve word variants: doi chi sach - hanh tinh chat ((nhung cong) or (bang cong)) dan ((toan cao) or (toan tap))*.