Perhaps you should try some spelling variations:
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
cuu tre » cua tre, cau tren, cau treo
tinh vi » trinh vi, tinh voi, tinh va
su tien » su kien, su hien, tu tieng
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
luc va » duc va, tuc va
loc va » hoc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ky lang xa hoi. hieu va cuoc ((luc va) OR (loc va)) tinh vi ((cuu tre) or (su tien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky lang xa hoi. hieu va cuoc ((luc va) OR (loc va)) tinh vi ((cuu tre) OR (su tien)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky lang xa hoi. hieu va cuoc ((luc va) OR (loc va)) tinh vi ((cuu tre) or (su tien))".
• Adding a wildcard symbol may retrieve word variants: so sach ky lang xa hoi. hieu va cuoc ((luc va) OR (loc va)) tinh vi ((cuu tre) or (su tien))*.