I'm hoping someone on this list has the quick answer that will end my 
frustration ;-).

I loaded some BIBFRAME records into Protege (desktop, 5.0, because 
earlier versions have problems in the RDF->OWL transform). I have this data:

_:genid4 <> 
<> .
_:genid5 <> 
<> .
_:genid5 <> "Morrow" .
_:genid4 <> _:genid5 .
<> _:genid4

[more readable version]

:instance27 bf:publication _:genid4 .
_:genid4 bf:providerName _:genid5 .
_:genid5 bf:label "Morrow" .

I want to create a SPARQL query that will select the labels for 
bf:providerName. I thought it would be:

SELECT ?subject ?label
     WHERE { ?subject bf:providerName ?bnode .
         ?bnode bf:label ?label . }

But it turns out that this doesn't work. As I understand it, it is 
because blank nodes are "unnamed" and therefore do not identify a 
particular entity, and cannot be used more than once in a query. See: [1][2]

I've hit a dead-end, but surely there is a solution -- possibly right in 
front of me but I'm not seeing it.



Karen Coyle
[log in to unmask]
m: 1-510-435-8234
skype: kcoylenet