BJÖRK L., ERIKSON U., INGELMAN B. and ZAAR B. (1974) “Improved Polymeric Contrast Agents for Roentgenologic Examination of the Gastrointestinal Tract: I. Preliminary Report on the Chemistry of the Polymers”, Upsala Journal of Medical Sciences, 79(2), pp. 103-105. doi: 10.3109/03009737409178976.