Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
hanh hoi » hanh thoi, hanh noi, hanh hoa
ban hanh » ban hang
quoc ban » quoc bao, quoc lan, quoc quan
cam quoc » cac quoc, cao quoc, nam quoc
hoi cua » hoi chuc
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
nang xa » nang x, lang xa, nang ma
sai ky » sac ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach ty) or (sai ky)) nang xa hoi. ((hieu ve) or (hieu qua)) cam quoc ban hanh hoi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sai ky)) nang xa hoi. ((hieu ve) OR (hieu qua)) cam quoc ban hanh hoi cua viet.
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) or (sai ky)) nang xa hoi. ((hieu ve) or (hieu qua)) cam quoc ban hanh hoi cua viet*.