Lot Essay
Cf. F. Fremersdorf and E. Polonyi-Fremersdorf, Die Farblosen Gläser der Frühzeit in Köln, Köln, 1984, pp. 81-82, nos. 185-187; and N. Kunina, Ancient Glass in the Hermitage Collection, The State Hermitage, 1997, p. 308 ff., nos. 274-277, for similar.