Investigation of the microstructure of Thick-GEMs with single photo-electronsGergő Hamar, Silvia Dalla Torre, Shuddha Shankar Dasgupta, Stefano Levorato, Fulvio Tessarotto and Dezső VargaEPJ Web Conf., 174 (2018) 03006DOI: https://doi.org/10.1051/epjconf/201817403006