Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
thuc va » thuc vat, thuc dan, thuc day
vai cua » hai cua, lai cua, bai cua
va dan » ca dan, va dao, va dau
x hoi » xa hoi, o hoi, 5 hoi
ve am » va am

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: tu sach ky nang ((x hoi) OR (x ho)). hieu ve am thuc va dan ((vai cua) OR (dai cua)) triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((x hoi) or (x ho)). hieu ve am thuc va dan ((vai cua) OR (dai cua)) triet~".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((x hoi) or (x ho)). hieu ve am thuc va dan ((vai cua) OR (dai cua)) triet*.