Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
te sach » toc sach
dai cuu » dai cua, dai huu
va hanh » van hanh, va danh, ban hanh
cac duc » cac du, cao duc, cac dac
hieu va » lieu va, hieu qua
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
cuu tre » cua tre, cau tren, cau treo
o hoi » co hoi, o hoc, o hai
x hoi » xa hoi, x ho, 5 hoi

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: te sach ty nang ((x hoi) OR (o hoi)). hieu va cac duc ((va hanh) OR (va thanh)) dai cuu tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty nang ((x hoi) OR (o hoi)). hieu va cac duc ((va hanh) or (va thanh)) dai cuu tre~".
• Adding a wildcard symbol may retrieve word variants: te sach ty nang ((x hoi) OR (o hoi)). hieu va cac duc ((va hanh) or (va thanh)) dai cuu tre*.