Perhaps you should try some spelling variations:
hieu quan » lieu quan, thien quan, lien quan
sang mai » sang ma, sang tai, lang mai
bo sach » hoc sach
hanh va » hang va, hanh vi
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
ca viet » va viet, co viet, hoa viet
mai hoi » mai khoi, dai hoi, lai hoi
ky sang » ky nang, ky dang, ky tang
co sach » cuon sach, hoc sach
va ca » va cac, va cao, va cai

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((bo sach) OR (co sach)) ky sang mai hoi. ((hieu qua) or (hieu quan)) am thuc va hanh va ca viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((bo sach) OR (co sach)) ky sang mai hoi. ((hieu qua) OR (hieu quan)) am thuc va hanh va ca viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((bo sach) OR (co sach)) ky sang mai hoi. ((hieu qua) or (hieu quan)) am thuc va hanh va ca viet".
• Adding a wildcard symbol may retrieve word variants: ((bo sach) OR (co sach)) ky sang mai hoi. ((hieu qua) or (hieu quan)) am thuc va hanh va ca viet*.