Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
hanh vai » hanh vi, hanh va, hanh tai
vai cua » dai cua, hai cua, lai cua
thuc va » thuc vat, thuc dan, thuc day
van cau » van dau, van hau, van chat
sach ky » sac ky, sach y, sach kem
lang xa » lang ha, dang xay, lang van
sach ty » sach y, sach tu, sach thu
cua tre » cua te, cuu tre, cua triet
tac va » tac da, tac xa, tuc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: so ((sach ky) or (sach ty)) lang xa hoi. hieu van cau ((tac va) or (thuc va)) hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so ((sach ky) OR (sach ty)) lang xa hoi. hieu van cau ((tac va) OR (thuc va)) hanh vai cua tre.
• Adding a wildcard symbol may retrieve word variants: so ((sach ky) or (sach ty)) lang xa hoi. hieu van cau ((tac va) or (thuc va)) hanh vai cua tre*.