Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
thuc dan » thuc hanh, hoc dan, thuc vat
dan vanh » dan canh, dan hanh, dang hanh
vanh dai » van dai, vanh tai, lanh dao
tu cach » tu cac
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
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: ((tu cach) or (su sach)) ky nang xa hoi. hieu van nam thuc dan vanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu cach) OR (su sach)) ky nang xa hoi. hieu van nam thuc dan vanh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu cach) or (su sach)) ky nang xa hoi. hieu van nam thuc dan vanh dai cua tre*.