Perhaps you should try some spelling variations:
thuoc va » thuoc ma, thuong va, thuoc tai
hanh lai » hanh lam, hanh tai, thanh lap
lai cua » dai cua, hai cua, lai chau
thuc va » thuc vat, thuc dan, thuc day
tu sach » thu sach, su sach, te sach
va bach » va cach, vu bach, va bac
hieu va » lieu va, hieu qua
ly nang » ky nang, ly hang, ly vang
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, v nang, may nang
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 ((y nang) OR (ly nang)) x hoi. hieu va bach ((thuoc va) or (thuc va)) hanh lai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((y nang) OR (ly nang)) x hoi. hieu va bach ((thuoc va) OR (thuc va)) hanh lai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((y nang) OR (ly nang)) x hoi. hieu va bach ((thuoc va) or (thuc va)) hanh lai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ((y nang) OR (ly nang)) x hoi. hieu va bach ((thuoc va) or (thuc va)) hanh lai cua tre*.