Perhaps you should try some spelling variations:
sach song » sach dung
hanh dai » hanh tai, hanh dao, vanh dai
van hanh » van thanh, ban hanh, van anh
thi hanh » thi thanh
thi lan » thi nang, thi lien
duc van » duc va, duc tan, duc manh
nam duc » nam duoc, pham duc, nam thuc
cua tre » cua te, cuu tre, cua triet
sach so » mach so, sach lo, sach dao
xay hoi » xa hoi, tay hoi, cay phoi

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 so) or (sach song)) van xay hoi. ((thi hanh) or (thi lan)) nam duc van hanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach so) OR (sach song)) van xay hoi. ((thi hanh) OR (thi lan)) nam duc van hanh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: thu ((sach so) or (sach song)) van xay hoi. ((thi hanh) or (thi lan)) nam duc van hanh dai cua tre*.