author = { Liebknecht, Karl Liebknecht, Wilhelm },

title = { Briefe an seinen Sohn Helmi },

publisher = {Werden u. Wirken},

year = {1947},

booktitle = {Die Perlenschnur ; Grosse in Briefen},

address = { Weimar },

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