Ceglarska-Jóźwiak, Joanna. 2019. “Contractor’s Specific Problems of Social Insurance in the Context of the Lack of the contractor’s Obligation to Personally Provide Work”. Acta Universitatis Lodziensis. Folia Iuridica 88 (September):157-66. https://doi.org/10.18778/0208-6069.88.14.