author = { SPSS, Inc AND SPSS, Inc. Chicago, Ill },

title = { SPSS Base 9.0 userś guide },

publisher = {SPSS},

isbn = {0130203904},

keywords = { SPSS Computer file , Social sciences Statistical methods Computer programs , SPSS },

year = {1999},

address = { Chicago, Ill. },

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