Perhaps you should try some spelling variations:
van thanh » van tuan
ban thanh » ban hanh, ban hang
hanh hai » thanh hai, nhanh hai, hang hai
van hanh » ban hanh, van anh, van ban
hai cua » thai cua, dai cua, hoi cua
luc van » luoc van, luu van, duc van
su sach » so sach, vu sach
cao hoc » co hoc, cho hoc, chat hoc
cao hoi » cau hoi, co hoi, tao hoi
cua tre » cua te, cuu tre, cua triet
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang

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 v nang ((cao hoi) OR (cao hoc)). hieu ((van thanh) or (ban thanh)) luc van hanh hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach v nang ((cao hoi) OR (cao hoc)). hieu ((van thanh) OR (ban thanh)) luc van hanh hai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach v nang ((cao hoi) OR (cao hoc)). hieu ((van thanh) or (ban thanh)) luc van hanh hai cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach v nang ((cao hoi) OR (cao hoc)). hieu ((van thanh) or (ban thanh)) luc van hanh hai cua tre*.