Norberg , B., A. Norberg, U. Parkhede, H. Gippert, and M. Åkerman. “The Effect of Short-Term High-Dose Treatment With Methenamine Hippurate of Urinary Infection in Geriatric Patients With Indwelling Catheters: I. The Preparation and Morphology of a Quantified Urine Sediment”. Upsala Journal of Medical Sciences, vol. 84, no. 1, Mar. 1979, pp. 67-74, doi:10.3109/03009737909179141.