Perhaps you should try some spelling variations:
thieu nien » thien nhien
hieu hien » bieu hien, dieu hien, chieu chien
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
va hanh » van hanh, va thanh, va danh
cua tre » cuu tre, cua triet, dua tren
cac tu » cac thu, cach tu, cac du
cua te » cua tu
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: tu sach ky nang x hoi. ((thieu nien) or (hieu hien)) cac tu va hanh vi ((cua tre) OR (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. ((thieu nien) OR (hieu hien)) cac tu va hanh vi ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang x hoi. ((thieu nien) or (hieu hien)) cac tu va hanh vi ((cua tre) OR (cua te))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x hoi. ((thieu nien) or (hieu hien)) cac tu va hanh vi ((cua tre) OR (cua te))*.