Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
sach ty » sach y, sach tu, sach thu
cua tre » cua te, cua triet, dua tren
dao via » dao va, dao viet, dao giao
thuc va » thuc vat, thuc dan, thuc day
su sach » so sach, vu sach
qua nam » quan nam, cua nam, quang nam
lang xa » lang ha, dang xay, lang van
cuu tre » cau tren, cau treo
va dao » 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: su sach ty ((lang xa) or (van xay)) hoi. hieu qua nam thuc va dao via ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty ((lang xa) OR (van xay)) hoi. hieu qua nam thuc va dao via ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty ((lang xa) or (van xay)) hoi. hieu qua nam thuc va dao via ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: su sach ty ((lang xa) or (van xay)) hoi. hieu qua nam thuc va dao via ((cua tre) OR (cuu tre))*.