Innovationsverhalten der deutschen Industrie : Ergebnisse des ifo Innovationstests 1990 - 1997
Penzkofer, Horst, (1999)
Estimation of the depreciation rate of physical and R&D capital in the US total manufacturing sector
Nadiri, Mohammed Ishaq, (1996)
Research in industry, its organization and management
Furnas, Clifford C., (1948)
