Perhaps you should try some spelling variations:
thanh dat » thanh san, thanh hai, thanh van
thanh dai » thanh hai, thanh tai, thanh oai
hieu van » hieu va, thien van, lieu va
cac van » cac dan
van cac » van hac, van cau, van bac
cua tre » cua te, cuu tre, cua triet
cac cac » cac cach, ca cac, cac bac
sach v » sach va, sach y, sach vay
sach 2 » sach y
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: thu ((sach v) or (sach 2)) nang x hoi. hieu van cac cac van ((thanh dai) OR (thanh dat)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach v) OR (sach 2)) nang x hoi. hieu van cac cac van ((thanh dai) OR (thanh dat)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((sach v) or (sach 2)) nang x hoi. hieu van cac cac van ((thanh dai) OR (thanh dat)) cua tre".
• Adding a wildcard symbol may retrieve word variants: thu ((sach v) or (sach 2)) nang x hoi. hieu van cac cac van ((thanh dai) OR (thanh dat)) cua tre*.