Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
hai cua » thai cua, dai cua, hoi cua
sai cua » dai cua, lai cua, bai cua
nam dan » nam dinh
thu nam » tu nam, thu nhap, thu nhat
hiem he » hiem xe, thien he, hiem cho
hieu he » hieu ve, hieu le, hieu hien
sang ma » tang ma, nang ma, sang tao
ty sang » ty xang, ty hang, duy sang
ma hoi » mai hoi, xa hoi, ma hoa

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 ty sang ma hoi. ((hieu he) OR (hiem he)) nam thu nam dan ((sai cua) or (hai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty sang ma hoi. ((hieu he) OR (hiem he)) nam thu nam dan ((sai cua) OR (hai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty sang ma hoi. ((hieu he) OR (hiem he)) nam thu nam dan ((sai cua) or (hai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ty sang ma hoi. ((hieu he) OR (hiem he)) nam thu nam dan ((sai cua) or (hai cua)) tre*.