[1] https://www.neopost.de/sites/neopost.de/files/ppl45_fuer_website.pdf[2] https://www.deutschepost.de/content/dam/dpag/images/P_p/Premiumadress/downloads/dp-premiumadress-produktschluessel-122019.pdf [3] https://www.deutschepost.de/content/dam/dpag/images/D_d/dialogpost/downloads/dp-broschuere-dialogpost-01-2020.pdf