Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
sach ky » sac ky, sach y, sach ty
ky tang » ky nang, ky dang, kho tang
tang xa » trang xa, tang ma, lang xa
thuc va » thuc vat, thuc dan, thuc day
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
va dan » ca dan, va dao, va dau

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 tang xa hoi. hieu ((va nam) or (va nay)) thuc va dan vai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ky tang xa hoi. hieu ((va nam) OR (va nay)) thuc va dan vai cuu tre.
• Adding a wildcard symbol may retrieve word variants: doc sach ky tang xa hoi. hieu ((va nam) or (va nay)) thuc va dan vai cuu tre*.