Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
thuc va » thuc vat, thuc dan, thuc day
cua tre » cua te, cuu tre, cua triet
ly nang » ky nang, ly hang, ly vang
va cam » va cham, va cac, va cai
y nang » ky nang, v nang, may nang
va cao » va cac, va co, va dao
va dau » va dao
dau di » da di, dau da, dau do
di cua » dai cua, doi cua, de cua

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)) xa hoi. hieu ((va cam) or (va cao)) thuc va dau di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((y nang) OR (ly nang)) xa hoi. hieu ((va cam) OR (va cao)) thuc va dau di cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ((y nang) or (ly nang)) xa hoi. hieu ((va cam) or (va cao)) thuc va dau di cua tre*.