Adams 2002, p. 118, pl. 38c–d; Łajtar 2015–2016, p. 129 (no. 28); Obłuski 2019, table 3, sub 5
colour photos available at <http://www.medievalnubia.info/dev/index.php/File:6K3-641r.JPG> (recto) and <http://www.medievalnubia.info/dev/index.php/File:6K3-641v.JPG> (verso);