Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
ky tang » ky nang, ky dang, kho tang
lai hoi » dai hoi, lai hoa, lai roi
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
ky sang » ky nang, ky dang, duy sang
vai cau » van cau, vai cac, lai chau
xuc va » duc va, tuc va, luc va
va cau » van cau, va cac, va dau
va cam » va cham, va cac, va cao

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: thuoc sach ((ky sang) OR (ky tang)) lai hoi. hieu va cam xuc va hanh ((vai cau) OR (va cau)) tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ((ky sang) or (ky tang)) lai hoi. hieu va cam xuc va hanh ((vai cau) OR (va cau)) tren~".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ((ky sang) or (ky tang)) lai hoi. hieu va cam xuc va hanh ((vai cau) OR (va cau)) tren*.