Perhaps you should try some spelling variations:
lang van » dang van, tang van, hoang van
va gianh » van giang, va giai, va thanh
tu sach » thu sach, su sach, te sach
cac hoc » cach hoc, cac hop, bac hoc
lai cua » dai cua, hai cua, lai chau
va gian » van gian, va giai, va gia
hieu ve » hieu va, hieu van
lang xa » lang ha, dang xay
ve cac » va cac, vien cac
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach y ((lang xa) OR (lang van)) hoi. hieu ve cac hoc ((va gianh) or (va gian)) lai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y ((lang xa) OR (lang van)) hoi. hieu ve cac hoc ((va gianh) OR (va gian)) lai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y ((lang xa) OR (lang van)) hoi. hieu ve cac hoc ((va gianh) or (va gian)) lai cua te".
• Adding a wildcard symbol may retrieve word variants: tu sach y ((lang xa) OR (lang van)) hoi. hieu ve cac hoc ((va gianh) or (va gian)) lai cua te*.