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