Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
hanh dai » hanh tai, hanh dao, vanh dai
thuc day » thuc dan, thuc vat
thuc va » thuc vat, thuc dan
hieu ha » hieu hoa, hieu va, hieu ca
su sach » so sach, vu sach
cua tre » cua te, cuu tre, cua triet
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai

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: ((thuoc sach) OR (su sach)) ky nang o hoi. hieu ha nam ((thuc va) OR (thuc day)) hanh dai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thuoc sach) or (su sach)) ky nang o hoi. hieu ha nam ((thuc va) OR (thuc day)) hanh dai cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((thuoc sach) or (su sach)) ky nang o hoi. hieu ha nam ((thuc va) OR (thuc day)) hanh dai cua tre*.