Zyznarska-Dworczak, Beata. “Determinants for the Development of Non-Financial Reporting and Its External Verification in the Light of Accounting Theory and Practice”. Studia Oeconomica Posnaniensia, vol. 5, no. 6, June 2017, pp. 136-49, https://doi.org/10.18559/SOEP.2017.6.8.