Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
thu bang » thu ban, chu bang, thu trang
hanh lai » hanh lam, hanh tai, thanh lap
thu hang » thi hang, thuc hanh, thu huong
van hanh » van thanh, ban hanh, van anh
cac dac » cac dan, cac dai, cac bac
lai cua » dai cua, hai cua, lai chau
cac duc » cac du, cao duc, cac nuoc
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. lieu va ((cac duc) or (cac dac)) van hanh 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. lieu va ((cac duc) OR (cac dac)) van hanh lai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((thu bang) OR (thu hang)) xa hoi. lieu va ((cac duc) or (cac dac)) van hanh lai cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ((thu bang) OR (thu hang)) xa hoi. lieu va ((cac duc) or (cac dac)) van hanh lai cua tre*.