Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu va » hieu qua
cac toc » cac toi, cac nuoc, cac thoi
van mat » van dat, van man, van mao
mat cua » ma cua, manh cua, mang cua
cua tre » cua te, cuu tre, cua triet
toc va » hoc va, toc ta, tuc va
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky nang x hoi. ((hieu va) or (lieu va)) cac toc va van mat cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. ((hieu va) OR (lieu va)) cac toc va van mat cua tre*.