All proteins in UniProt database of an organism

Statement: 

Retrieve all proteins included in UniProt database of a specific organism (e.g mus musculus) $name$. Limit of results per page (e.g.20) $number$

Query: 
PREFIX uniprot: <http://purl.uniprot.org/> PREFIX up:<http://purl.uniprot.org/core/> SELECT ?protein ?organism ?name WHERE { ?protein a up:Protein . ?protein up:organism ?organism . ?organism up:scientificName ?name . FILTER regex(?name, "??name", "i") } limit ??number