Perhaps you should try some spelling variations:
thien van » thi van
hanh dai » hanh tai, hanh dao, vanh dai
hau truc » cau truc, hang truc, hoc truc
tu cach » tu cac
va hanh » van hanh, va thanh, va danh
truc va » thuc va, thuc vat, trung va
van hau » van ha, van hai, van dau
cua tre » cua te, cuu tre, cua triet
tang ma » mang may, tang van
nang ma » sang ma, nang cao, mang may
su sach » so sach, vu sach

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 cach) OR (su sach)) ky ((nang ma) OR (tang ma)) hoi. thien van hau truc va hanh dai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu cach) or (su sach)) ky ((nang ma) OR (tang ma)) hoi. thien van hau truc va hanh dai cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((tu cach) or (su sach)) ky ((nang ma) OR (tang ma)) hoi. thien van hau truc va hanh dai cua tre*.