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

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