Determination of pH distribution through pH-related properties in deacidified model paper Izabela Vajová, Katarína Vizárová, Radko Tiňo, Nad’a Krivoňáková, Zdenko Takáč and Svetozár Katuščák Eur. Phys. J. Plus, 136 5 (2021) 578 Published online: 25 May 2021 DOI: 10.1140/epjp/s13360-021-01495-9