Perhaps you should try some spelling variations:
toc sach » hoc sach, thuoc sach, nuoc sach
nam thuc » nam thuoc, am thuc, nam thu
cau treo » cau theo, cau tren, cau triet
doc sach » hoc sach, nuoc sach, dac sac
lang xa » lang ha, dang xay, lang van
long ha » dong ha, cong ha, dong hoa
hieu va » lieu va, hieu qua
thuc ca » thuc cua, thuc can, thuc cao
dan vai » dan va, dan tai, dan vat
vai cau » va cau, van cau, vai cac
va nam » van nam, ha nam, va nay
ca dan » cac dan, ca dao

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) OR (doc sach)) y ((lang xa) or (long ha)) hoi. hieu va nam thuc ca dan vai cau treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (doc sach)) y ((lang xa) OR (long ha)) hoi. hieu va nam thuc ca dan vai cau treo.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (doc sach)) y ((lang xa) or (long ha)) hoi. hieu va nam thuc ca dan vai cau treo".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) OR (doc sach)) y ((lang xa) or (long ha)) hoi. hieu va nam thuc ca dan vai cau treo*.