Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
hanh vai » hanh vi, hanh va, hanh tai
ty nang » ty xang, ty hang, ly nang
hieu va » lieu va, hieu qua
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
lao va » tao va, cao va, bao va
lo va » lo van, ly va, le va

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach ((ty nang) OR (ky nang)) xa hoi. hieu va cac ((lo va) or (lao va)) hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ((ty nang) OR (ky nang)) xa hoi. hieu va cac ((lo va) OR (lao va)) hanh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ((ty nang) OR (ky nang)) xa hoi. hieu va cac ((lo va) or (lao va)) hanh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ((ty nang) OR (ky nang)) xa hoi. hieu va cac ((lo va) or (lao va)) hanh vai cua tre*.