Bagnato, G. ., Ruggeri, R. ., Certo, R. ., Piccione, C. ., Carerj, S. ., & Roberts, W. . (1969). Serum thyroxine levels are associated with increased systolic pulmonary arterial pressure in systemic sclerosis. Clinical and Experimental Rheumatology, 35 Suppl 106(4), 220. Retrieved from http://www.clinexprheumatol.org/pubmed/find-pii.asp?pii=28598782 (Original work published 1969)