Perhaps you should try some spelling variations:
thanh va » thanh van, hanh va, thanh ha
te sach » toc sach
cac thu » cach thuc, cac thoi
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
lang xa » dang xay, lang van
lang ha » long ha
cu tren » tu tren, dua tren
cac tu » cach tu, cac du, tac tu
va cu » va cau, va chu, va su

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 ((lang xa) or (lang ha)) hoi. hieu ve ((cac tu) OR (cac thu)) gia thanh va cu tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky ((lang xa) OR (lang ha)) hoi. hieu ve ((cac tu) OR (cac thu)) gia thanh va cu tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky ((lang xa) or (lang ha)) hoi. hieu ve ((cac tu) OR (cac thu)) gia thanh va cu tren".
• Adding a wildcard symbol may retrieve word variants: te sach ky ((lang xa) or (lang ha)) hoi. hieu ve ((cac tu) OR (cac thu)) gia thanh va cu tren*.