Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
thu bang » thu ban, chu bang, thu trang
thu hang » thi hang, thuc hanh, thu huong
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
duc van » duc va, duc tan, duc manh
van anh » van thanh, tuan anh, van minh
anh lai » anh bai, anh tai, gianh lai
lai cua » dai cua, hai cua, lai chau
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ((thu bang) or (thu hang)) xa hoi. hieu va cac duc van anh lai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((thu bang) OR (thu hang)) xa hoi. hieu va cac duc van anh lai cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ((thu bang) or (thu hang)) xa hoi. hieu va cac duc van anh lai cua tre*.