@prefix dcterms: <http://purl.org/dc/terms/> .
@prefix ex: <https://hendrikborgelt.github.io/Draft_for_IUPAC_CIAAW-Isotopic-Abundances-and-Atomic-Weights/sparql/queries/> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix schema: <https://schema.org/> .
@prefix sh: <http://www.w3.org/ns/shacl#> .
@prefix spex: <https://purl.expasy.org/sparql-examples/ontology#> .

ex:5_05-provenance a sh:SPARQLExecutable, sh:SPARQLSelectExecutable;
  rdfs:comment """ Declarations and their sources
 Every declaration that cites a report, with the year when it is known.""";
  rdfs:label "Declarations and their sources";
  sh:prefixes _:sparql_examples_prefixes;
  sh:select """PREFIX dcterms: <http://purl.org/dc/terms/>
SELECT ?declaration ?year ?source WHERE {
  ?declaration dcterms:source ?source .
  OPTIONAL { ?declaration dcterms:issued ?year }
}
ORDER BY ?declaration""";
  schema:keywords "declarations", "provenance" .