Perhaps you should try some spelling variations:
thanh gian » thanh giang, thach giang, thanh san
van thanh » ban thanh, van tuan
gian cua » gian xu, ban cua
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
cac bac » cac bai, cac ban, cac cach
cac duc » cac du, cao duc, cac dac
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky nang ((o hoi) or (xa hoi)). hieu ve ((cac duc) or (cac bac)) van thanh gian cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang ((o hoi) OR (xa hoi)). hieu ve ((cac duc) OR (cac bac)) van thanh gian cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ((o hoi) or (xa hoi)). hieu ve ((cac duc) or (cac bac)) van thanh gian cua tre*.