Perhaps you should try some spelling variations:
sang tao » hang tai
te sach » toc sach
sach ky » sac ky, sach y, sach ty
ky sang » ky nang, ky dang, ky tang
tao hoi » tao khoi, tao boi, tay hoi
hieu ve » hieu va, hieu van
dinh vi » dinh ve, dinh viet, dinh tri
luc va » tuc va, loc va
vi cua » vai cua, di cua

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: te sach ky sang tao hoi. ((hieu ve) OR (hieu qua)) cam ((luc va) OR (duc va)) dinh vi cua vat~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky sang tao hoi. ((hieu ve) or (hieu qua)) cam ((luc va) OR (duc va)) dinh vi cua vat~".
• Adding a wildcard symbol may retrieve word variants: te sach ky sang tao hoi. ((hieu ve) or (hieu qua)) cam ((luc va) OR (duc va)) dinh vi cua vat*.