A. Zaccaria, G. Latinakis, M. Oliveri, T. Maio, G. Frisone, and F. Versace, “The support of the ultrasonography of the shoulder in the diagnosis of polymyalgia rheumatica with normal erythrocyte sedimentation rate”, Reumatismo, vol. 61, no. 4, pp. 290–297, Sep. 2009.