GNUSOWSKI , Marek. The Business Services Industry in the Context Of Professional Services - the Relationship Approach. Studia Oeconomica Posnaniensia, Poznan, Polska, v. 6, n. 4, p. 63–78, 2026. DOI: 10.18559/SOEP.2018.4.4. Disponível em: https://journals.ue.poznan.pl/soep/article/view/3806. Acesso em: 3 sep. 2026.