Cost of Debt for Private Firms Revisited: Voluntary Audits as a Reflection of Risk
R. Ichev, J. Koren, U. Kosi, K. Sitar Sustar, A. Valentincic, Cost of Debt for Private Firms Revisited: Voluntary Audits as a Reflection of Risk, 2021.

Accounting quality in private firms during the transition towards international standards
A. Valentincic, A. Novak, U. Kosi, Accounting in Europe 14 (2017) 358–387.

Does Financial Statement Audit Reduce the Cost of Debt of Private Firms?
U. Kosi, J. Koren, A. Valentincic, in: 2013.