@prefix pr: <http://www.wikidata.org/prop/reference/> .
@prefix wdref: <http://www.wikidata.org/reference/> .

wdref:b8ec3921d36c8be4dce2a84dd7b16699ab3d761f pr:P854 <https://books.google.com/books?id=sZfGYsrEIBEC> .