Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh vai » hanh vi, hanh va, hanh tai
tu cong » thu cong, te cong, tai cong
cong xa » cong xay, cong xua, cong ha
hieu va » lieu va, hieu qua
cao duc » dao duc, cao suc, giao duc
xa hanh » xa thanh, xa khanh, va hanh
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
va cao » va cac, va co, va dao
duc xa » duoc xa, tuc xa, duc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (toc sach)) tu cong xa hoi. hieu va cao duc xa hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) tu cong xa hoi. hieu va cao duc xa hanh vai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) tu cong xa hoi. hieu va cao duc xa hanh vai cua tre*.