author = { Williams, Heidi L. National Bureau of Economic Research },

title = { How Do Patents Affect Research Investments? },

publisher = {National Bureau of Economic Research},

year = {January 2017},

booktitle = {NBER working paper series ; no. w23088},

address = { Cambridge, Mass },

url = { http://slubdd.de/katalog?TN_libero_mab2 }