Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa
te sach » toc sach
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cuu tre, cua triet
cac tuc » cac toc, cac tac, cac nuoc
hieu ve » hieu va, hieu van
dang ma » dang mau, dang mam, dang mat
ky dang » ky nang, ky danh
cac tu » cac thu, cach tu, cac du
ma hoi » mai hoi, xa hoi, ma hoa

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 ky dang ma hoi. hieu ve ((cac tuc) or (cac tu)) va ((thanh hai) OR (thanh san)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky dang ma hoi. hieu ve ((cac tuc) OR (cac tu)) va ((thanh hai) OR (thanh san)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky dang ma hoi. hieu ve ((cac tuc) or (cac tu)) va ((thanh hai) OR (thanh san)) cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky dang ma hoi. hieu ve ((cac tuc) or (cac tu)) va ((thanh hai) OR (thanh san)) cua tre*.