Book: van den Bossche, Willy. 2001 Antique Glass Bottles: their history and evolution (1500-1850). 439.
• An English "twins" flask: p. 370, pl. 308, c. 1820,Book: Lu, Zhangshen. 2012 Passion for Porcelain: Masterpieces of Ceramics from the British Museum and the Victoria and Albert Museum.
• 1690-1700 Chinese export porcelain and European glass examples: pp. 118-19, no. 019, figs. 1-3, the glass examples from 17th C.