A langyao vase of this form, but of slightly larger size (17 in.), is illustrated in the Catalogue of the Morgan Collection of Chinese Porcelains, New York 1911, vol. II, pl. CXXXVII, and another of this type is illustrated in, Qing Dynasty Monochrome Porcelains in the National Palace Museum, Taipei, 1981, no. 1, where the shape is described as guanyin zun. See, also, the vase included in the S. Marchant & Son exhibition, Imperial Porcelain of Kangxi, Yongzheng and Qianlong, London, 9 - 25 June 1996, no. 3, previously in the collection of Stephen Junkunc III and sold at Christie's New York, 21 September 1995, lot 228.