Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
nam thuc » nam thuoc, nam thu, nam tu
tinh doi » trinh doc, trinh do, tinh hoc
sach lo » sach dao, sach doi, sach hoi
lo lang » o lang, so lang, le lang
lang xa » lang ha, dang xay, lang van
hieu ve » hieu va, hieu van
va tinh » may tinh
cua tre » cuu tre, cua triet, dua tren
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: toc sach lo lang xa hoi. hieu ve ((nam thuc) OR (am thuc)) va tinh doi ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach lo lang xa hoi. hieu ve ((nam thuc) OR (am thuc)) va tinh doi ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach lo lang xa hoi. hieu ve ((nam thuc) OR (am thuc)) va tinh doi ((cua tre) or (cua te))".
• Adding a wildcard symbol may retrieve word variants: toc sach lo lang xa hoi. hieu ve ((nam thuc) OR (am thuc)) va tinh doi ((cua tre) or (cua te))*.