Zupan Hajna, N., P. Pruner, A. Mihevc, P. Schnabl, in P. Bosák. „Cave Sediments from Postojnska–Planinska Cave System (Slovenia): Evidence of Multi-Phase Evolution in Epiphreatic Zone“. Acta Carsologica, let. 37, št. 1, junij 2008, doi:10.3986/ac.v37i1.160.