Perhaps you should try some spelling variations:
dang vat » dang van, dong vat, dang nhat
nam thuc » nam thuoc, am thuc, nam thu
cau tren » cu tren, dau tren, ca tren
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
sach ky » sach y, sach ty, sach kem
thuc va » thuc vat, thuc dan, thuc day
dan vai » dan va, dan tai, dan vat
sac ky » cac ky, sai ky
va nam » van nam, ha nam, va nay

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) OR (sac ky)) lang xa hoi. hieu va nam thuc va ((dan vai) or (dang vat)) cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach ky) OR (sac ky)) lang xa hoi. hieu va nam thuc va ((dan vai) OR (dang vat)) cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc ((sach ky) OR (sac ky)) lang xa hoi. hieu va nam thuc va ((dan vai) or (dang vat)) cau tren".
• Adding a wildcard symbol may retrieve word variants: toc ((sach ky) OR (sac ky)) lang xa hoi. hieu va nam thuc va ((dan vai) or (dang vat)) cau tren*.