van Dooren-Greebe, R J, et al. “Interruption of Long-Term Methotrexate Treatment in Psoriasis. Evaluation of Clinical Course and Laboratory Parameters After Discontinuation and Reintroduction of Weekly Oral Methotrexate”. Acta Dermato-Venereologica, vol. 75, no. 5, Sept. 1995, pp. 393-6, doi:10.2340/0001555575393396.