Piwowarczyk, Renata, and Łukasz Krajewski. “Orobanche Lutea Baumg. (Orobanchaceae) in Poland: Revised Distribution, Taxonomy, Phytocoenological and Host Relations”. Biodiversity: Research and Conservation, vol. 34, Mar. 2015, pp. 17-39, doi:10.2478/biorc-2014-0008.