Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa, thanh san
thanh tai » thanh toan, doanh tai, thanh san
cai cach » loi cach, tai cac, va cach
cach ban » cac ban, cach bao, cach ben
tu sach » thu sach, te sach, tu cach
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
nang ro » nang co, nang ho, nang ra
su sach » so sach, vu sach
ro hoi » co hoi, o hoi, mo hoi
y nang » ky nang, ly nang, v nang
va cai » va cac, va bai, va dai

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 (su sach)) y nang ro hoi. hieu va cai cach ban ((thanh tai) or (thanh hai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) y nang ro hoi. hieu va cai cach ban ((thanh tai) OR (thanh hai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (su sach)) y nang ro hoi. hieu va cai cach ban ((thanh tai) or (thanh hai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (su sach)) y nang ro hoi. hieu va cai cach ban ((thanh tai) or (thanh hai)) cua tre*.