Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van phan » van phong, van thanh, luan phan
phan duc » pham duc, phan tu, phan dau
hanh vai » hanh vi, hanh tai, hanh van
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
hanh va » hang va, hanh vi
cua tre » cua te, cuu tre, cua triet

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

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