@prefix x: <http://example.org/ns#> .
@prefix : <http://example.org/books#> .
@prefix dc:         <http://purl.org/dc/elements/1.1/> .

:book1 dc:title "TITLE 1" .
:book1 x:price  10 .

:book2 dc:title "TITLE 2" .
:book2 x:price  20 .

:book3 dc:title "TITLE 3" .