Similar examples inscribed with the numeral si (four) are included in important public collections. Compare with one in the National Palace Museum, Taibei, in the Illustrated Catalogue of Sung Dynasty Porcelain, pl. 66; one in the Tokyo National Museum can be found in Tregear, Song Ceramics, pl. 171. Yet another 'drum nail' bowl similarly inscribed was included in the Exhibition of Important Chinese Ceramics from the Robert Chang Collection, Christie's London, 1993, Catalogue, no. 6