Perhaps you should try some spelling variations:
hanh dai » hanh tai, hanh dao, vanh dai
truc va » thuc va, thuc vat, trung va
va cham » va chat, va tham
hieu va » lieu va, hieu qua
sach ty » sach tu, sach thu, xach tay
nang o » nang co, nang ho, nang ro
cua te » cua tu
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 ty) OR (sach y)) nang o hoi. hieu va cham ((truc va) OR (tuc xa)) hanh dai cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ty) OR (sach y)) nang o hoi. hieu va cham ((truc va) or (tuc xa)) hanh dai cua te~".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) OR (sach y)) nang o hoi. hieu va cham ((truc va) or (tuc xa)) hanh dai cua te*.