Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
hoc sach » hoc sinh, hoc cac, hoc anh
va thanh » gia thanh, ban thanh, va tinh
dieu cua » dieu tra
hieu cua » hieu qua, bieu cua, hieu ca
lang xa » lang ha, dang xay, lang van
sach ty » sach y, sach tu, sach thu
ca viet » va viet, co viet, hoa viet
cac co » cac cong
ang xa » mang xa, dang xay, hoang xa
tai ca » tai cac, tai cao, tai cua
co va » co ma, do va, so va

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

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