Norberg A., Norberg B., Parkhede U., Gippert H., and Ekman R. “The Effect of Short-Term High-Dose Treatment With Methenamine Hippurate of Urinary Infection in Geriatric Patients With Indwelling Catheters: II. Evaluation by Means of a Quantified Urine Sediment”. Upsala Journal of Medical Sciences, vol. 84, no. 1, Mar. 1979, pp. 75-82, doi:10.3109/03009737909179142.