Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
nam thuc » nam thuoc, am thuc, nam thu
cau treo » cau theo, cau tren, cau triet
lang ha » long ha
lang xa » dang xay, lang van
hieu ca » hieu cac, hieu cua, hieu va
sach ky » sac ky, sach y, sach ty
thuc va » thuc vat, thuc dan, thuc day
dan tai » van tai, dan thi, han tai
cuu tre » cua tre, cau tren
va dan » ca dan, va dao, va dau
ca nam » cua nam, cai nam, ha nam

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 ky ((lang xa) OR (lang ha)) hoi. hieu ca nam thuc va dan tai ((cuu tre) or (cau treo))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky ((lang xa) OR (lang ha)) hoi. hieu ca nam thuc va dan tai ((cuu tre) OR (cau treo))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky ((lang xa) OR (lang ha)) hoi. hieu ca nam thuc va dan tai ((cuu tre) or (cau treo))*".