Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
nam thuc » nam thuoc, am thuc, nam thu
thuc dan » thuc hanh, hoc dan, thuc vat
lang xa » lang ha, dang xay, lang van
hanh va » hang va, hanh vi
cua tre » cuu tre, cua triet, dua tren
y lang » o lang, _ lang, tay lang
va nam » van nam, ha nam, va nay
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 y lang xa hoi. lieu va nam thuc dan ((anh va) OR (hanh va)) ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y lang xa hoi. lieu va nam thuc dan ((anh va) OR (hanh va)) ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y lang xa hoi. lieu va nam thuc dan ((anh va) OR (hanh va)) ((cua tre) or (cua te))".
• Adding a wildcard symbol may retrieve word variants: toc sach y lang xa hoi. lieu va nam thuc dan ((anh va) OR (hanh va)) ((cua tre) or (cua te))*.