Perhaps you should try some spelling variations:
doi chinh » do chinh, tai chinh, hoc chinh
trinh vat » trinh van, trinh luat, sinh vat
hang cong » dang cong, hang nong, bang cong
trinh va » trinh van, trinh ve, trinh vi
cong san » cong tac
san chan » san chang, dan chan, san chay
chan ban » can ban, chat ban, chan nan

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi chinh sach - hanh ((trinh va) or (trinh vat)) hang cong san chan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi chinh sach - hanh ((trinh va) OR (trinh vat)) hang cong san chan ban.
• Adding a wildcard symbol may retrieve word variants: doi chinh sach - hanh ((trinh va) or (trinh vat)) hang cong san chan ban*.