Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
va thanh » gia thanh, ban thanh, le thanh
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
ky tang » ky nang, ky dang, kho tang
tang xa » trang xa, tang ma, lang xa
van cau » van dau, van hau, van chat
va tinh » may tinh
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: su sach ky tang xa hoi. hieu van cau truc ((va thanh) OR (va tinh)) va ((cua tre) OR (cua vat))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky tang xa hoi. hieu van cau truc ((va thanh) OR (va tinh)) va ((cua tre) or (cua vat))~".
• Adding a wildcard symbol may retrieve word variants: su sach ky tang xa hoi. hieu van cau truc ((va thanh) OR (va tinh)) va ((cua tre) or (cua vat))*.