Perhaps you should try some spelling variations:
day thanh » dao thanh, dat thanh, da thanh
thanh doi » thanh loi, thanh moi, thanh do
cua triet » cua viet, su triet, va triet
toc sach » doc sach, thuoc sach, nuoc sach
hoc sach » hoc sinh, hoc cac, hoc anh
nay thu » nam thu, tay thu, nay tu
thu day » thuc day, thu da, thu dac
cua tre » cua te, cuu tre, dua tren
va nay » va ngay, va cay
x hoi » xa hoi, o hoi, x ho

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) or (hoc sach)) ky nang x hoi. lieu va nay thu day thanh doi ((cua tre) OR (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc sach)) ky nang x hoi. lieu va nay thu day thanh doi ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) or (hoc sach)) ky nang x hoi. lieu va nay thu day thanh doi ((cua tre) OR (cua triet))".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (hoc sach)) ky nang x hoi. lieu va nay thu day thanh doi ((cua tre) OR (cua triet))*.