Perhaps you should try some spelling variations:
manh hanh » xanh hanh, danh thanh, minh thanh
hanh thai » nhanh thai, hinh thai, hanh tai
thai cua » than cua, tai cuc, tri cua
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cuu tre, cua triet
ve cao » ve bao, ve cac, ve co
va cao » va cac, va co, va dao
x hoi » o hoi, x ho, 5 hoi

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 ky nang ((x hoi) OR (xa hoi)). hieu ((ve cao) or (va cao)) suc manh hanh thai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((x hoi) OR (xa hoi)). hieu ((ve cao) OR (va cao)) suc manh hanh thai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((x hoi) OR (xa hoi)). hieu ((ve cao) or (va cao)) suc manh hanh thai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((x hoi) OR (xa hoi)). hieu ((ve cao) or (va cao)) suc manh hanh thai cua tre*.