How to solve duplicate resources?

I have executed this query to understand number of companies per industries:

select ?industry, (COUNT(?org) as ?NORG)
   ?org a <> .
    ?org <> ?industry .
GROUP BY ?industry

The response shows a large number of industries with very similar names, that looks as duplicated resources (e.g. :dbpedia/3D_printing and :dbpedia/3D_Printing or :dbpedia/Telecomunication and :dbpedia/Telecomunications).

However, it does not looks as a data quality problem as they resolved to unique resources (:dbpedia/3D_printing in the case of the first example and :dbpedia/Telecommunication for the second).

So, how can I change my query to eliminate “duplicates” and count them together?

Thank you very much in advance