“The subjective scope of voluntary improvements in Social Security: unequal treatment between workers. Comment on Supreme Court Ruling 877/2022, of 31 October (appeal 50/2019)” (2023) Revista de Derecho de la Seguridad Social, Laborum, (36), pp. 125–130. Available at: https://revista.laborum.es/index.php/revsegsoc/article/view/727 (Accessed: 6 November 2026).