Perhaps you should try some spelling variations:
cau triet » cau trieu, su triet, cua triet
lang van » dang van, tang van, hoang van
nam thuc » nam thuoc, am thuc, nam thu
doc sach » hoc sach, toc sach, nuoc sach
lang xa » lang ha, dang xay
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
thuc va » thuc vat, thuc dan, thuc day
dan vat » dang vat, van vat, dan va
vat cau » dat cau, va cau, van cau
va nam » van nam, ha nam, va nay
va dan » ca dan, va dao, va dau

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: doc sach ky ((lang xa) or (lang van)) hoi. hieu va nam thuc va dan vat cau triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ky ((lang xa) OR (lang van)) hoi. hieu va nam thuc va dan vat cau triet.
• Adding a wildcard symbol may retrieve word variants: doc sach ky ((lang xa) or (lang van)) hoi. hieu va nam thuc va dan vat cau triet*.