Frietsch, RainerRainerFrietschRammer, ChristianChristianRammerSchubert, TorbenTorbenSchubert2024-01-162024-01-162015https://publica.fraunhofer.de/handle/publica/23921310.1007/s10272-015-0521-7en330Heterogeneity of innovation systems in Europe and Horizon 2020journal article