Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
thanh da » thanh dat, thanh dam, thanh dan
hoc gia » hoc giao, hoc giai, toc gia
va chat » van chat, va phat, cao chat
sach ty » sach y, sach tu, sach thu
so sach » so sanh, bo sach, co sach
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
va cham » va tham
da cau » dat cau, va cau

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 ((nang xa) or (lang xa)) hoi. lieu ((va cham) OR (va chat)) hoc gia thanh da cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty ((nang xa) OR (lang xa)) hoi. lieu ((va cham) OR (va chat)) hoc gia thanh da cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ty ((nang xa) or (lang xa)) hoi. lieu ((va cham) OR (va chat)) hoc gia thanh da cau tren".
• Adding a wildcard symbol may retrieve word variants: so sach ty ((nang xa) or (lang xa)) hoi. lieu ((va cham) OR (va chat)) hoc gia thanh da cau tren*.