Andrey A. Sinjushin, Maria E. Ploshinskaya: Flower development in Lythrum salicaria L., Cuphea ignea A. DC. and C. hyssopifolia Kunth (Lythraceae): the making of monosymmetry in hexamerous flowers. In: Wulfenia. 27, 2020, S. 303–320, online auf researchgate.net.