Perhaps you should try some spelling variations:
thuc dan » thuc hanh, hoc dan, thuc vat
vanh tai » van tai, hanh tai, anh tai
vanh dai » van dai, lanh dao, van dao
tu sach » thu sach, su sach, te sach
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
thuc va » thuc vat, thuc day
hieu va » lieu va, hieu qua
va nam » van nam, ha nam, va nay
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: tu sach ky nang o hoi. hieu va nam ((thuc va) OR (thuc dan)) ((vanh dai) OR (vanh tai)) cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang o hoi. hieu va nam ((thuc va) OR (thuc dan)) ((vanh dai) or (vanh tai)) cua tre~".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang o hoi. hieu va nam ((thuc va) OR (thuc dan)) ((vanh dai) or (vanh tai)) cua tre*.