Identification of imported products and imitations as exemplified by pottery from medieval stronghold in Napole, parish Kowalewo Pomorskie, site 1 (Toruń voivodeship) - Poliński, Dariusz (Imported and locally produced pottery: methods of identification and analysis. (Materials from 1st Conference of Pottery Research Group of Committee for Pre- and Protohistoric Sciences of Polish Academy of Sciences.)., 1997)