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