This query returns every paper in the dataset with the length of title and the number of authors.

select ?paper ?lenoftitle ?numofpersons
where
{
    {
        select ?paper ?lenoftitle
        where
        {
            ?paper <http://purl.org/dc/elements/1.1/title> ?title . 
            BIND (STRLEN(?title) as ?lenoftitle)
        }
        order by asc(?paper)
    }
    {
        select ?paper (count(?person) as ?numofpersons)
        where 
        {
            ?paper <http://xmlns.com/foaf/0.1/maker> ?person . 
        }
        group by ?paper
        order by asc(?paper)
    }
}

This query returns number of papers per organization.

select ?univ (count(?paper) as ?numofpapers) 
where
{
    ?person <http://swrc.ontoware.org/ontology#affiliation> ?univuri . 
    ?univuri rdfs:label ?univ . 
    ?person  <http://xmlns.com/foaf/0.1/made> ?paper . 
}
group by ?univ
order by asc(?numofpapers)

This query returns the number of papers, each author has published.

select ?person (count(?paper) as ?numofpapers) 
where
{
    ?person <http://xmlns.com/foaf/0.1/name> ?name .
    ?person <http://xmlns.com/foaf/0.1/made> ?paper . 
}
group by ?person
order by asc(?numofpapers)

This query returns the number of papers per country

select ?country (count(distinct ?paper) as ?numofpapers) 
where
{
    ?person <http://xmlns.com/foaf/0.1/based_near> ?country . 
    ?person <http://xmlns.com/foaf/0.1/made> ?paper . 
}
group by ?country
order by asc(?numofpapers)