Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
thuc day » thuc dan, thuc vat
lang xa » lang ha, dang xay, lang van
sach ky » sac ky, sach y, sach ty
thuc va » thuc vat, thuc dan
ky lang » ky nang, ky dang, ky tang
dan vai » dan va, dan tai, dan vat
vai cuu » vai cua
cuu tre » cua tre, cau tren, cau treo
va nam » van nam, ha nam
va nay » va ngay, va cay

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: doc sach ky lang xa hoi. hieu ((va nam) OR (va nay)) ((thuc va) or (thuc day)) dan vai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ky lang xa hoi. hieu ((va nam) OR (va nay)) ((thuc va) OR (thuc day)) dan vai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc sach ky lang xa hoi. hieu ((va nam) OR (va nay)) ((thuc va) or (thuc day)) dan vai cuu tre".
• Adding a wildcard symbol may retrieve word variants: doc sach ky lang xa hoi. hieu ((va nam) OR (va nay)) ((thuc va) or (thuc day)) dan vai cuu tre*.