Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
hanh vai » hanh vi, hanh va, hanh tai
dam thuc » am thuc, dan thuc, nam thuc
tu sach » thu sach, su sach, te sach
vai cua » dai cua, hai cua, lai cua
xa hanh » xa thanh, xa khanh, va hanh
ty nang » ky nang, ty hang, ly nang
cua tre » cua te, cuu tre, cua triet
cam tu » cam thu, nam tu, dam tu

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 ((ty nang) OR (ty xang)) xa hoi. hieu van ((dam thuc) or (cam tu)) xa hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty nang) OR (ty xang)) xa hoi. hieu van ((dam thuc) OR (cam tu)) xa hanh vai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ty nang) OR (ty xang)) xa hoi. hieu van ((dam thuc) or (cam tu)) xa hanh vai cua tre*".