Perhaps you should try some spelling variations:
hieu tieng » viet tieng, dien tieng, tiep tieng
hieu hien » bieu hien, dieu hien, chieu chien
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
bac va » ban va, bao va, tac va
vi cua » vai cua, di cua

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang xa hoi. ((hieu tieng) OR (hieu hien)) cac ((bac va) OR (bac ha)) hanh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang xa hoi. ((hieu tieng) or (hieu hien)) cac ((bac va) OR (bac ha)) hanh vi cua tre~".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang xa hoi. ((hieu tieng) or (hieu hien)) cac ((bac va) OR (bac ha)) hanh vi cua tre*.