Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
sach tru » sach truc, sach thu, sach tu
hanh vai » hanh vi, hanh tai, hanh van
hanh va » hang va, hanh vi
lam cua » nam cua, lam chat
van lam » van nam
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
lang ha » long ha
cua tre » cua te, cuu tre, cua triet

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 tru ((nang xa) OR (lang ha)) hoi. hieu van lam cua ban ((hanh vai) OR (hanh va)) cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach tru ((nang xa) or (lang ha)) hoi. hieu van lam cua ban ((hanh vai) OR (hanh va)) cua tre~".
• Adding a wildcard symbol may retrieve word variants: tu sach tru ((nang xa) or (lang ha)) hoi. hieu van lam cua ban ((hanh vai) OR (hanh va)) cua tre*.