BJÖRK L., ERIKSON U., FALK J., INGELMAN B., and LINDBLAD G. “Improved Polymeric Contrast Agents for Roentgenologic Examination of the Gastrointestinal Tract: II. Preliminary Report on Animal Investigations”. Upsala Journal of Medical Sciences, vol. 79, no. 2, June 1974, pp. 106-8, doi:10.3109/03009737409178977.