The Tarskian ideas on logical constants are discussed, among other places, in Simons (1987), Sher (1991), (2008), Feferman (1999), Gómez-Torrente (2002), Bellotti (2003), Casanovas (2007), Bonnay (2008), (2014), Dutilh Novaes (2014), Sagi (forthcoming), and the entry on   logical constants.