Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
dang xay » dang van, van xay
hieu van » thien van, lieu va, hieu ve
vai cua » dai cua, hai cua, lai cua
va danh » va dinh, va dan, va hanh
ma danh » ma dan, mo danh, dia danh
cua tre » cua te, cuu tre, cua triet
da duoc » tao duoc, hoa duoc
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
xay hoi » xa hoi, tay hoi, cay phoi
ky dang » ky nang, ky danh

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: toc sach ky dang xay hoi. ((hieu van) OR (hieu va)) da duoc ((ma danh) OR (va danh)) vai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky dang xay hoi. ((hieu van) or (hieu va)) da duoc ((ma danh) OR (va danh)) vai cua tre~".
• Adding a wildcard symbol may retrieve word variants: toc sach ky dang xay hoi. ((hieu van) or (hieu va)) da duoc ((ma danh) OR (va danh)) vai cua tre*.