Perhaps you should try some spelling variations:
hanh thai » nhanh thai, hinh thai, hanh tai
thai cua » than cua, tai cuc, tri cua
so sach » so sanh, bo sach, co sach
va hanh » van hanh, va thanh, va danh
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu van
ky tang » ky nang, ky dang, kho tang
ky lang » ky nang, ky dang, tay lang
xuc va » duc va, tuc va, luc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ((ky lang) OR (ky tang)) xa hoi. ((hieu ve) or (hieu va)) bac xuc va hanh thai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ((ky lang) OR (ky tang)) xa hoi. ((hieu ve) OR (hieu va)) bac xuc va hanh thai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ((ky lang) OR (ky tang)) xa hoi. ((hieu ve) or (hieu va)) bac xuc va hanh thai cua tre".
• Adding a wildcard symbol may retrieve word variants: so sach ((ky lang) OR (ky tang)) xa hoi. ((hieu ve) or (hieu va)) bac xuc va hanh thai cua tre*.