Vries, A.H. de, Boute, M.C., Kuppen, M.C.P, Merriënboer, J.J.G. van, Koldewijn, E.L., Pelger, R.C.M., Wagner, C. Patient safety risks of basic urological procedures performed by junior and senior residents. Journal of Surgical Education: 2015, 72(5), 918-926