Treatment retention of infliximab and etanercept originators versus their corresponding biosimilars: Nordic collaborative observational study of 2334 biologics naïve patients with spondyloarthritis. - Lindström U; Glintborg B; Di Giuseppe D; Nordström D; Aarrestad Provan S; Gudbjornsson B; Askling J; Lund Hetland M; Aaltonen K; Krogh NS; Geirsson AJ; Jacobsson LTH (RMD open, 2019)