Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
hieu van » thien van, lieu va, hieu ve
hanh vai » hanh vi, hanh va, hanh tai
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
thuc va » thuc vat, thuc dan, thuc day
vai cua » dai cua, hai cua, lai cua
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: thuat sach ky nang xa hoi. ((hieu van) or (hieu va)) cau ((thuc va) or (hoc dan)) hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ky nang xa hoi. ((hieu van) OR (hieu va)) cau ((thuc va) OR (hoc dan)) hanh vai cua tre.
• Adding a wildcard symbol may retrieve word variants: thuat sach ky nang xa hoi. ((hieu van) or (hieu va)) cau ((thuc va) or (hoc dan)) hanh vai cua tre*.