Perhaps you should try some spelling variations:
minh hoa » minh hoang, trinh hoa, sinh hoat
so sach » so sanh, bo sach, co sach
hieu va » lieu va, hieu qua
hoa cua » hoa chat, hoa xuat
ty hang » ly hang, ty xang, thi hang
ty mang » ty xang, tin mang, tri mang
xuc va » duc va, tuc va, xac va
luc va » duc va, tuc va, loc va
va cao » va cac, va co, va dao

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 ((ty mang) or (ty hang)) xa hoi. hieu va cao ((xuc va) OR (luc va)) minh hoa cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ((ty mang) OR (ty hang)) xa hoi. hieu va cao ((xuc va) OR (luc va)) minh hoa cua vat.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ((ty mang) or (ty hang)) xa hoi. hieu va cao ((xuc va) OR (luc va)) minh hoa cua vat".
• Adding a wildcard symbol may retrieve word variants: so sach ((ty mang) or (ty hang)) xa hoi. hieu va cao ((xuc va) OR (luc va)) minh hoa cua vat*.