Perhaps you should try some spelling variations:
hieu hien » bieu hien, dieu hien, chieu chien
hieu vien » hieu viec, thieu nien, hieu tieng
hanh vai » hanh vi, hanh va, hanh tai
cuu tre » cau tren, cau treo
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cua triet, dua tren
cac tuc » cac toc, cac tu, cac tac
tuc va » thuc va, truc va, tuc xa
sac ky » cac ky, sai ky
tu sac » tu sach, tu cac, tu san

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 (hieu hien)) cac tuc va hanh vai ((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 (hieu hien)) cac tuc va hanh vai ((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 (hieu hien)) cac tuc va hanh vai ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: tu sac ky nang x ho. ((hieu vien) or (hieu hien)) cac tuc va hanh vai ((cua tre) OR (cuu tre))*.