Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
hai cua » thai cua, dai cua, hoi cua
sai cua » dai cua, lai cua, bai cua
le danh » le dinh, le anh, le manh
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
ky sang » ky nang, ky dang, ky tang
ve nam » he nam, va nam, le nam
thu le » thu les, thu xe, tu le
ma hoi » mai hoi, ma hoa, me hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky sang ((ma hoi) OR (xa hoi)). hieu ve nam thu le danh ((sai cua) or (hai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky sang ((ma hoi) OR (xa hoi)). hieu ve nam thu le danh ((sai cua) OR (hai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky sang ((ma hoi) OR (xa hoi)). hieu ve nam thu le danh ((sai cua) or (hai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky sang ((ma hoi) OR (xa hoi)). hieu ve nam thu le danh ((sai cua) or (hai cua)) tre*.