Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa, thanh san
thien van » thi van
thanh dai » thanh tai, thanh dat, thanh oai
hieu van » hieu va, lieu va, hieu ve
te sach » toc sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
cua tre » cua te, cuu tre, cua triet
du va » dau va, tu va, su 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 ty nang x hoi. ((hieu van) OR (thien van)) cac du va ((thanh dai) or (thanh hai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty nang x hoi. ((hieu van) OR (thien van)) cac du va ((thanh dai) OR (thanh hai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty nang x hoi. ((hieu van) OR (thien van)) cac du va ((thanh dai) or (thanh hai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ty nang x hoi. ((hieu van) OR (thien van)) cac du va ((thanh dai) or (thanh hai)) cua tre*.