Perhaps you should try some spelling variations:
thuc dan » thuc hanh, hoc dan, thuc vat
tu sach » thu sach, su sach, te sach
va cham » va chat, va tham
dan dau » danh dau, doan dau, van dau
dau dai » dat dai, sau dai, dau da
cua tre » cua te, cuu tre, cua triet
y nang » ly nang, v nang, may nang
va cao » va cac, va co, va dao

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 (ky nang)) xa hoi. hieu ((va cham) or (va cao)) thuc dan dau dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((y nang) OR (ky nang)) xa hoi. hieu ((va cham) OR (va cao)) thuc dan dau dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((y nang) OR (ky nang)) xa hoi. hieu ((va cham) or (va cao)) thuc dan dau dai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ((y nang) OR (ky nang)) xa hoi. hieu ((va cham) or (va cao)) thuc dan dau dai cua tre*.