Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
nam thuc » nam thuoc, am thuc, nam thu
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
thuc va » thuc vat, thuc dan, thuc day
y lang » o lang, _ lang, tay lang
va nam » van nam, ha nam, va nay
va dan » ca dan, va dao, va dau
va cua » va chua, via cua, ma cua
ca cua » co 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 y lang xa hoi. hieu va nam thuc va dan ((va cua) OR (ca cua)) tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y lang xa hoi. hieu va nam thuc va dan ((va cua) OR (ca cua)) tre".
• Adding a wildcard symbol may retrieve word variants: toc sach y lang xa hoi. hieu va nam thuc va dan ((va cua) OR (ca cua)) tre*.