“The National Social Security Institute Can Declare the Joint and Several Liability of a City Council With Respect to a Debt Contracted by a Commercial Company in Bankruptcy When It Acts in a Similar Way to So-Called ‘company Groups’”. Revista de Derecho de la Seguridad Social, Laborum, no. 24, Sept. 2020, pp. 137-51, https://revista.laborum.es/index.php/revsegsoc/article/view/422.