J. L. Hurtado-Alegre, J. M. Crispin-Ayala, J. del P. Alvarez-Canto, and J. F. Quispe-Pari, “Purple urine bag syndrome: report of an unusual case in a patient with a chronic indwelling urinary catheter”, Rev Peru Med Exp Salud Publica, vol. 43, no. 1, pp. 138–42, Feb. 2026, doi: 10.17843/rpmesp.2026.431.15050.