Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
kinh va » kinh van, tinh va, sinh va
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
ty hang » ly hang, ty xang, thi hang
ty nang » ky nang, ty xang, ly nang
xuc va » duc va, tuc va, xac va
luc va » duc va, tuc va, loc va
va cua » va chua, via cua, ca cua
va cam » va cham, va cac, va cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ((ty nang) or (ty hang)) xa hoi. hieu va cam ((xuc va) or (luc va)) kinh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((ty nang) OR (ty hang)) xa hoi. hieu va cam ((xuc va) OR (luc va)) kinh va cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ((ty nang) or (ty hang)) xa hoi. hieu va cam ((xuc va) or (luc va)) kinh va cua tre*.