Perhaps you should try some spelling variations:
thanh di » thanh doi, thanh de, thanh do
toc sach » hoc sach, doc sach, thuoc sach
tay lang » tai lang, tay tang, tay quang
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
lang xa » lang ha, dang xay, lang van
ve cam » ve cham, ve cac, va cam
di cua » dai cua, doi cua, de cua

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) or (toc sach)) tay lang xa hoi. hieu ve cam ((tu van) OR (tu va)) thanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) tay lang xa hoi. hieu ve cam ((tu van) OR (tu va)) thanh di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) tay lang xa hoi. hieu ve cam ((tu van) OR (tu va)) thanh di cua tre".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) tay lang xa hoi. hieu ve cam ((tu van) OR (tu va)) thanh di cua tre*.