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 xa » lang ha, dang xay, lang van
tang xa » trang xa, tang ma, tang ha
hieu ca » hieu cac, hieu cua, hieu va
sach ty » sach y, sach tu, sach thu
thuc va » thuc vat, thuc dan, thuc day
dan vai » dan va, dan tai, dan vat
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 ty ((tang xa) OR (lang xa)) hoi. hieu ca nam thuc va dan vai ((cuu tre) or (cau treo))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ty ((tang xa) OR (lang xa)) hoi. hieu ca nam thuc va dan vai ((cuu tre) OR (cau treo)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ty ((tang xa) OR (lang xa)) hoi. hieu ca nam thuc va dan vai ((cuu tre) or (cau treo))".
• Adding a wildcard symbol may retrieve word variants: toc sach ty ((tang xa) OR (lang xa)) hoi. hieu ca nam thuc va dan vai ((cuu tre) or (cau treo))*.