Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa, thanh san
thanh hoi » thanh hoai, thanh hoa, thanh loi
cham doc » cham soc, chat doc, chau doc
va cham » va chat, va tham
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
doc va » duoc va, hoc va, duc va
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach y) or (sach 2)) nang x hoi. hieu va cham doc va ((thanh hoi) OR (thanh hai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach y) OR (sach 2)) nang x hoi. hieu va cham doc va ((thanh hoi) OR (thanh hai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach y) or (sach 2)) nang x hoi. hieu va cham doc va ((thanh hoi) OR (thanh hai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: te ((sach y) or (sach 2)) nang x hoi. hieu va cham doc va ((thanh hoi) OR (thanh hai)) cua tre*.