Perhaps you should try some spelling variations:
nuoc sach » nguoi sach, hoc sach, cuoc cach
sach ky » sac ky, sach y, sach ty
qua cac » cua cac
vai cua » dai cua, lai cua, bai cua
hai cua » thai cua, dai cua, hoi cua
x hoi » xa hoi, o hoi, x ho
bo va » bao va, so va, co va
do va » do van, so va

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

• Performing a fuzzy search may retrieve terms with similar spellings: nuoc sach ky nang x hoi. hieu qua cac ((bo va) OR (do va)) thanh ((vai cua) or (hai cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: nuoc sach ky nang x hoi. hieu qua cac ((bo va) OR (do va)) thanh ((vai cua) OR (hai cua)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "nuoc sach ky nang x hoi. hieu qua cac ((bo va) OR (do va)) thanh ((vai cua) or (hai cua)) triet".
• Adding a wildcard symbol may retrieve word variants: nuoc sach ky nang x hoi. hieu qua cac ((bo va) OR (do va)) thanh ((vai cua) or (hai cua)) triet*.