Munde, T., Brand, S., Hidalgo, W., Maddula, R. K., Svatoš, A., & Schneider, B. (2013). Biosynthesis of tetraoxygenated phenylphenalenones in Wachendorfia thyrsiflora. Phytochemistry, 91, 165-176. doi:10.1016/j.phytochem.2012.02.020.