Perhaps you should try some spelling variations:
nham thuc » nhan thuc, nam thuc, nham thu
toc sach » hoc sach, doc sach, thuoc sach
hanh vai » hanh vi, hanh va, hanh tai
hieu van » thien van, lieu va, hieu ve
su sach » so sach, vu sach
vai cua » dai cua, hai cua, lai cua
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) or (toc sach)) ky nang xa hoi. ((hieu van) OR (hieu va)) nham thuc va hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (toc sach)) ky nang xa hoi. ((hieu van) OR (hieu va)) nham thuc va hanh vai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (toc sach)) ky nang xa hoi. ((hieu van) OR (hieu va)) nham thuc va hanh vai cua tre*".