Mandarakas_et_al_Astron. Astrophys._623_2019.pdfhttp://purl.tuc.gr/dl/dias/FAF35655-4BFC-44E5-862A-C62C676E716CSearch for AGN counterparts of unidentified Fermi -LAT sources with optical polarimetry: demonstration of the techniquefree2020-07-27application/pdf819.9 kB