"B-Objects". B-Objects. Federal Office for Cultural Protection (BABS). 1 January 2018. Archived from the original on 7 January 2017. Retrieved 1 October 2019.
"B-Objects". B-Objects. Federal Office for Cultural Protection (BABS). 1 January 2018. Archived from the original on 7 January 2017. Retrieved 1 October 2019.