Perhaps you should try some spelling variations:
lang van » dang van, tang van, hoang van
nam thuc » nam thuoc, am thuc, nam thu
vai cua » dai cua, hai cua, lai cua
dan vai » dan va, dan tai, dan vat
thuc va » thuc vat, thuc dan, thuc day
hieu va » lieu va, hieu qua
sach ky » sac ky, sach ty, sach kem
lang xa » lang ha, dang xay
cua tre » cua te, cuu tre, cua triet
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: hoc ((sach ky) or (sach y)) ((lang xa) OR (lang van)) hoi. hieu va nam thuc va dan vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((sach ky) OR (sach y)) ((lang xa) OR (lang van)) hoi. hieu va nam thuc va dan vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((sach ky) or (sach y)) ((lang xa) OR (lang van)) hoi. hieu va nam thuc va dan vai cua tre".
• Adding a wildcard symbol may retrieve word variants: hoc ((sach ky) or (sach y)) ((lang xa) OR (lang van)) hoi. hieu va nam thuc va dan vai cua tre*.