Perhaps you should try some spelling variations:
hieu viec » nhieu viec, hieu ve, sieu viet
viec cac » vien cac, viec cua, viec lam
ban hanh » ban hang
lang van » dang van, tang van, hoang van
hai cua » thai cua, dai cua, hoi cua
va hanh » van hanh, va thanh, va danh
cac xuc » cam xuc, cac nuoc, chat xuc
tu sach » thu sach, su sach, te sach
lang xa » lang ha, dang xay
cua tre » cua te, cuu tre, cua triet
sach v » sach va, sach y, sach 2

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