Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
ky sang » ky nang, ky dang, ky tang
sang ma » tang ma, nang ma, sang tao
hieu he » hieu ve, hiem he, hieu hien
hieu le » hieu ve, hieu ly, tieu le
thu xay » thau xay, thuc xay, tu xay
sai cua » hai cua, lai cua, bai cua
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 ky sang ma hoi. ((hieu he) OR (hieu le)) nam thu xay dung ((sai cua) or (dai cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky sang ma hoi. ((hieu he) OR (hieu le)) nam thu xay dung ((sai cua) OR (dai cua)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky sang ma hoi. ((hieu he) OR (hieu le)) nam thu xay dung ((sai cua) or (dai cua)) triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky sang ma hoi. ((hieu he) OR (hieu le)) nam thu xay dung ((sai cua) or (dai cua)) triet*.