L. Sagi, M. Solomon, S. Baum, A. Lyakhovitsky, H. Trau, and A. Barzilai, “Evidence for Methotrexate as a Useful Treatment for Steroid-dependent Chronic Urticaria”, Acta Derm Venereol, vol. 91, no. 3, pp. 303–306, Mar. 2011.