Reference

Florian Schiestl, Manfred Ayasse, Hannes F. Paulus, D. Erdmann, Wittko Francke (1997): Variations of floral scent emission and post-pollination changes in individual flowers of Ophrys spegodes subsp. sphegodes (Orchidaceae). – J. Chem. Ecol. – 23(12): 2881 - 2895.