Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
thuc van » thuc vat, thuc dan, thuc hanh
dinh dai » dinh dat, sinh dai, dinh dao
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
van cac » van hac, van cau, van bac
thuc va » thuc vat, thuc dan, thuc day
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu ((sach ky) or (cac ky)) nang xa hoi. hieu van cac ((thuc van) or (thuc va)) dinh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ky) OR (cac ky)) nang xa hoi. hieu van cac ((thuc van) OR (thuc va)) dinh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: thu ((sach ky) or (cac ky)) nang xa hoi. hieu van cac ((thuc van) or (thuc va)) dinh dai cua tre*.