author = { Heath, Philip R. AND Kamps, Klaus Heiner },

title = { Lecture Notes in Mathematics: Groupoids and classification sequences },

publisher = {Springer Berlin Heidelberg},

isbn = {0075-8434},

isbn = {1617-9692},

year = {1979},

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