Nabuurs, C. H., Kievit, W., Labbé, N., Leemans, C. R., Smit, C. F. G. M., van den Brekel, M. W. M., Pauw, R. J., van der Laan, B. F. A. M., Jansen, J. C., Lacko, M., Braunius, W. W., Morita, S., Wierzbicka, M., Matoba, T., Hanai, N., Takes, R. P., & Kunst, H. P. M. (2020). evaluation of the modified Pittsburgh classification for predicting the disease‐free survival outcome of squamous cell carcinoma of the external auditory canal. Head & neck, 42(12), 3609–3622. http://access.bl.uk/ark:/81055/vdc_100116170232.0x000025