Perhaps you should try some spelling variations:
hieu cua » hieu qua, dieu cua, bieu cua
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
cua dao » ca dao, cua dan, cua dai
dao vuc » dao duc, dao tuc, dao vu
vuc van » duc van, luc van, thuc van
v nang » va nang, vu nang, van nang
cua tu » cua tuc, cua su, cua cu

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

• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((v nang) OR (cam nang)) xa hoi. hieu cua dao vuc van hanh vi ((cua te) OR (cua tu))~.
• Adding a wildcard symbol may retrieve word variants: su sach ((v nang) or (cam nang)) xa hoi. hieu cua dao vuc van hanh vi ((cua te) or (cua tu))*.