http://en.wikipedia.org/wiki/Category:Piano_makers
http://en.wikipedia.org/wiki/Category:Piano_manufacturing_companies
http://en.wikipedia.org/wiki/List_of_piano_makers
http://en.wikipedia.org/wiki/List_of_piano_brand_names
http://laguiadelpiano.com/lista-refencia-de-pianos/
http://pianosuite.es/