Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cua triet, dua tren
va hanh » van hanh, va thanh, va danh
cac toc » cac toi, cac nuoc, cac thoi
cuu tre » cau tren, cau treo
cac tuc » cac tu, cac tac, cac nuoc
x hoi » xa hoi, o hoi, x ho

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

• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang x hoi. hieu van ((cac tuc) OR (cac toc)) va hanh vi ((cua tre) OR (cuu tre))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang x hoi. hieu van ((cac tuc) or (cac toc)) va hanh vi ((cua tre) OR (cuu tre))~".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang x hoi. hieu van ((cac tuc) or (cac toc)) va hanh vi ((cua tre) OR (cuu tre))*.