1. Stephan, B.R., Wagner, I., and Kleinschmit, J. (2003). EUFORGEN Technical Guidelines for Genetic Conservation and Use for Wild Apple and Pear (Malus sylvestris and Pyrus pyraster), International Plant Genetic Resources Institute.
2. Wagner, I., and Büttner, R. (2016, January 17–21). Hybridization in wild pear (Pyrus pyraster) from various regions in Germany and from Luxembourg with respect to Pyrus × communis. Proceedings of the III International Symposium on Horticulture in Europe-SHE2016, Chania, Greece.
3. Ellenberg, H. (1983). Vegetation Mitteleuropas mit den Alpen in Ökologischer Sicht, Ulmer Verlag. [3rd ed.].
4. Bertová, L. (1992). Flóra Slovenska IV/3, Veda.
5. Hegi, G. (1995). Illustrierte Flora von Mitteleuropa, Blackwell Wissenschaft-Verlag.