Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
nam thuc » nam thuoc, am thuc, nam tu
sach tu » cach tu, sach ty, sach uu
lang xa » lang ha, dang xay, lang van
cua tre » cua te, cuu tre, cua triet
va dan » ca dan, va dao, va dau
dan va » doan va, dan ca, ban va
va cua » va chua, via cua, ca cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc ((sach tu) or (sach thu)) lang xa hoi. lieu va ((nam thuc) OR (nam thu)) va dan va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach tu) OR (sach thu)) lang xa hoi. lieu va ((nam thuc) OR (nam thu)) va dan va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc ((sach tu) or (sach thu)) lang xa hoi. lieu va ((nam thuc) OR (nam thu)) va dan va cua tre".
• Adding a wildcard symbol may retrieve word variants: toc ((sach tu) or (sach thu)) lang xa hoi. lieu va ((nam thuc) OR (nam thu)) va dan va cua tre*.