Perhaps you should try some spelling variations:
thanh doi » thanh loi, thanh moi, thanh do
thu sach » tu sach, thuat sach, thuoc sach
cam duc » cam xuc, cao duc, pham duc
anh doi » anh noi, anh doc, anh dong
duc ban » duc tan, duc van, dua ban
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
su sach » so sach, vu sach
nang o » nang co, nang ho, nang ro
va cam » va cham, va cac, va cao
o hai » co hai, so hai, o lai

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu sach) or (su sach)) ky nang o hai. hieu va cam duc ban ((anh doi) OR (thanh doi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (su sach)) ky nang o hai. hieu va cam duc ban ((anh doi) OR (thanh doi)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (su sach)) ky nang o hai. hieu va cam duc ban ((anh doi) OR (thanh doi)) cua tre".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (su sach)) ky nang o hai. hieu va cam duc ban ((anh doi) OR (thanh doi)) cua tre*.