Tyteca, D., Ceinos, M., Gathoye, J.-L., Brys, R. and Jacquemyn, H. (2012) “On the morphological, biological and genetic heterogeneity of the genus Orchis (Orchidaceae, Orchidinae)”, Phytotaxa. Auckland, New Zealand, 75(1), pp. 19–32. doi: 10.11646/phytotaxa.75.1.2.