Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cuu thuc » cuu tac
vat hanh » vat thanh, van hanh, va hanh
sach ky » sac ky, sach ty, sach kem
van cuu » van cau, van chu, van cu
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua
x hoi » xa hoi, o hoi, x ho

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: thu ((sach ky) or (sach y)) nang x hoi. hieu van cuu thuc vat hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ky) OR (sach y)) nang x hoi. hieu van cuu thuc vat hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: thu ((sach ky) or (sach y)) nang x hoi. hieu van cuu thuc vat hanh vi cua tre*.