Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
sang tao » hang tai
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
danh vi » hanh vi, dinh vi, danh di
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.

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ky sang tao hoi. ((hieu ve) or (hieu qua)) cam ((luc va) or (duc va)) danh vi cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky sang tao hoi. ((hieu ve) OR (hieu qua)) cam ((luc va) OR (duc va)) danh vi cua vat.
• Adding a wildcard symbol may retrieve word variants: toc sach ky sang tao hoi. ((hieu ve) or (hieu qua)) cam ((luc va) or (duc va)) danh vi cua vat*.