Perhaps you should try some spelling variations:
hanh dai » hanh tai, hanh dao, vanh dai
te sach » toc sach
dai cuu » dai cua, dai huu
va hanh » van hanh, va thanh, va danh
cac dac » cac dan, cac dai, cac bac
sach ty » sach y, sach tu, sach thu
cac duc » cac du, cao duc, cac nuoc
ty nang » ky nang, ty xang, ty hang
hieu va » lieu va, hieu qua
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.

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ty nang ((x hoi) OR (o hoi)). hieu va ((cac duc) or (cac dac)) va hanh dai cuu tre~.
• 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) OR (cac dac)) va hanh 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) or (cac dac)) va hanh dai cuu tre*".