Perhaps you should try some spelling variations:
thanh toan » thanh hoa, thanh san, tinh toan
thanh van » thanh san, thanh phan, thanh nhan
dieu tra » dieu tri, kiem tra, dieu cua
cac tuc » cac toc, cac tu, cac tac
tra cac » tra cau, tri cac, tranh cac
sach ty » sach y, sach thu, xach tay
lang xa » lang ha, dang xay, lang van
sach tu » sach thu, cach tu, sach uu
cua tre » cua te, cuu tre, cua triet
tuc va » thuc va, truc va, tuc xa

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

• Performing a fuzzy search may retrieve terms with similar spellings: so ((sach ty) OR (sach tu)) lang xa hoi. dieu tra cac tuc va ((thanh toan) or (thanh van)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so ((sach ty) OR (sach tu)) lang xa hoi. dieu tra cac tuc va ((thanh toan) OR (thanh van)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so ((sach ty) OR (sach tu)) lang xa hoi. dieu tra cac tuc va ((thanh toan) or (thanh van)) cua tre".
• Adding a wildcard symbol may retrieve word variants: so ((sach ty) OR (sach tu)) lang xa hoi. dieu tra cac tuc va ((thanh toan) or (thanh van)) cua tre*.