Perhaps you should try some spelling variations:
thanh toan » thanh hoa, thanh san, tinh toan
te sach » toc sach
tuc gia » tac gia, duc gia, toc gia
cac tuc » cac toc, cac tu, cac tac
hieu ve » hieu va, hieu van
sach ky » sac ky, sach y, sach ty
ky dang » ky nang, ky danh
cua tre » cua te, cuu tre, cua triet
ve cac » va cac, vien cac
ma hoi » mai hoi, ma hoa, me hoi

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) or (xa hoi)). hieu ve cac tuc gia ((thanh toan) or (doanh tai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky dang ((ma hoi) OR (xa hoi)). hieu ve cac tuc gia ((thanh toan) OR (doanh tai)) cua tre.
• Adding a wildcard symbol may retrieve word variants: te sach ky dang ((ma hoi) or (xa hoi)). hieu ve cac tuc gia ((thanh toan) or (doanh tai)) cua tre*.