Perhaps you should try some spelling variations:
bieu hien » dieu hien, dieu khien, bien phien
hieu vien » hieu hien, hieu viec, thieu nien
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky
cac tu » cac thu, cach tu, cac du

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sac ky nang x ho. ((hieu vien) or (bieu hien)) cac tu va hanh vi ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky nang x ho. ((hieu vien) OR (bieu hien)) cac tu va hanh vi ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky nang x ho. ((hieu vien) or (bieu hien)) cac tu va hanh vi ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: tu sac ky nang x ho. ((hieu vien) or (bieu hien)) cac tu va hanh vi ((cua tre) OR (cuu tre))*.