1. The dropped head syndrome;Suarez;Neurology,1992
2. Camptocormia and dropped head syndrome as a clinic picture of myotonic myopathy;Kocaaga;Joint Bone Spine,2008
3. Isolated neck extensor myopathy: a common cause of dropped head syndrome;Katz;Neurology,1996
4. Scleroderma (systemic sclerosis): classification, subsets and pathogenesis;LeRoy;J Rheumatol,1998
5. Assessment of disease activity;Valentini;Clin Exp Rheumatol,2003