Herschel-PACS photometry of faint stars for sensitivity performance assessment and establishment of faint FIR primary photometric standardsU. Klaas, Z. Balog, M. Nielbock, T.G. Müller, H. Linz and Cs. KissA&A, 613 (2018) A40DOI: https://doi.org/10.1051/0004-6361/201731812