“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, no. 36 (September): 125-30. https://revista.laborum.es/index.php/revsegsoc/article/view/727.