Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
hieu quang » thieu quang, hieu quan, hieu qua
hoang cong » hang cong, hoang long, hoang vuong
cap hoang » cam hoang, cau hoang, van hoang
cong cap » cung cap, cong cau, cong cac
cong tan » cong tac, cong san, cong thanh

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((chieu sach) or (hieu quang)) - thanh cong cap hoang cong tan ((toan ban) or (van ban))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chieu sach) OR (hieu quang)) - thanh cong cap hoang cong tan ((toan ban) OR (van ban)).
• Adding a wildcard symbol may retrieve word variants: ho ((chieu sach) or (hieu quang)) - thanh cong cap hoang cong tan ((toan ban) or (van ban))*.