Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
sach va » sach xa, sach ha, sach dao
hai cua » thai cua, dai cua, hoi cua
vai cua » dai cua, lai cua, bai cua
vu sach » vu bach, su sach, vu khach
hieu ve » hieu va, hieu van
va nang » van nang, da nang, cam nang
cac tu » cac thu, cach tu, cac du
tu van » tu va
ve cac » va cac, vien cac
x hoi » o hoi, x ho, 5 hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach va nang ((x hoi) OR (xa hoi)). hieu ve cac tu van thanh ((vai cua) or (hai cua)) viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach va nang ((x hoi) OR (xa hoi)). hieu ve cac tu van thanh ((vai cua) OR (hai cua)) viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach va nang ((x hoi) OR (xa hoi)). hieu ve cac tu van thanh ((vai cua) or (hai cua)) viet".
• Adding a wildcard symbol may retrieve word variants: vu sach va nang ((x hoi) OR (xa hoi)). hieu ve cac tu van thanh ((vai cua) or (hai cua)) viet*.