Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
cao hoi » cau hoi, co hoi, cao hoc
cam tuc » cam xuc, nam thuc, dam thuc
cua cau » cua cac, cua chu, cua cay
y nang » ky nang, ly nang, v nang
cam tu » cam thu, nam tu, dam tu
ca dan » cac dan, ca dao
ca cau » cac cau, can cau, ca cac

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: su sach y nang cao hoi. hieu van ((cam tuc) OR (cam tu)) ca dan ((ca cau) OR (cua cau)) tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang cao hoi. hieu van ((cam tuc) OR (cam tu)) ca dan ((ca cau) or (cua cau)) tren~".
• Adding a wildcard symbol may retrieve word variants: su sach y nang cao hoi. hieu van ((cam tuc) OR (cam tu)) ca dan ((ca cau) or (cua cau)) tren*.