G. V. S. Rao, L. R. Yannamreddy, G. V. K. C. Rao, and S. R. Cuddapah, “Aspergillus niger associated calcium oxalate otolith in the external auditory canal: an uncommon clinical presentation”, Int J Otorhinolaryngol Head Neck Surg, vol. 11, no. 5, pp. 613–615, Sep. 2025.