author = { Packham, Analisa National Bureau of Economic Research },

title = { Are Syringe Exchange Programs Helpful or Harmful? New Evidence in the Wake of the Opioid Epidemic },

publisher = {National Bureau of Economic Research},

year = {2019},

booktitle = {NBER working paper series ; no. w26111},

address = { Cambridge, Mass },

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