author = { Knetter, Michael M. National Bureau of Economic Research Slaughter, Matthew J. },

title = { Measuring Product-Market Integration },

publisher = {National Bureau of Economic Research},

year = {February 1999},

booktitle = {NBER working paper series ; no. w6969},

address = { Cambridge, Mass },

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