Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
vanh dai » vanh tai, lanh dao, van dao
hieu va » lieu va, hieu qua
van dai » van dao, van hai, can dai
cuu tre » cua tre, cau tren, cau treo
y nang » ky nang, ly nang, v nang
luc va » duc va, loc va
tuc va » thuc va, truc va, tuc xa
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: toc sach y nang x hoi. hieu va cac ((luc va) OR (tuc va)) ((vanh dai) OR (van dai)) cuu tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y nang x hoi. hieu va cac ((luc va) OR (tuc va)) ((vanh dai) or (van dai)) cuu tre~".
• Adding a wildcard symbol may retrieve word variants: toc sach y nang x hoi. hieu va cac ((luc va) OR (tuc va)) ((vanh dai) or (van dai)) cuu tre*.