File:Number of patent families in the fields of fuel cells and fuel cells in transportation compared to electric vehicles (EVs) and to EVs excluding hybrid vehicles.png
Number_of_patent_families_in_the_fields_of_fuel_cells_and_fuel_cells_in_transportation_compared_to_electric_vehicles_(EVs)_and_to_EVs_excluding_hybrid_vehicles.png (777 × 294 pixels, file size: 37 KB, MIME type: image/png)