The application of reduction coefficients of the usual retirement age in the railway sector. Regarding the Sentence of 21 June 2017 (Rec. 1281/2014), delivered by the Employment Division of the Supreme Court. (2018). Revista de Derecho de la Seguridad Social, Laborum, 14. https://revista.laborum.es/index.php/revsegsoc/article/view/272