@book{
title = {Arbeitsbuch 3},
author = {Keller, Susy},
editor = {De Barba, Graziella},
editor = {Funk, Hermann},
editor = {Koenig, Michael},
editor = {Koithan, Ute},
editor = {Mariotta, Maruska},
editor = {Scherling, Theo},
editor = {998015618708896 - Geni@l [3] : versione italiana - 1 -  },
year = {2007},
address = {Berlin [etc.] },
publisher = {Langenscheidt},
}