Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
mang xa » mang may, dang xay, mang cua
lang xa » lang ha, dang xay, lang van
hieu ve » hieu va, hieu van
cac toc » cac toi, cac nuoc, cac thoi
va danh » va dinh, va dan, va hanh
danh vi » hanh vi, dinh vi, danh di
cua tre » cua te, cuu tre, cua triet
ve cac » va cac, vien cac
toc va » hoc va, toc ta, tuc 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: tu sach ky ((mang xa) or (lang xa)) hoi. hieu ve cac toc va danh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((mang xa) OR (lang xa)) hoi. hieu ve cac toc va danh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((mang xa) or (lang xa)) hoi. hieu ve cac toc va danh vi cua tre*.