Reference
Hans C. M. Den Nijs, Henry Hooghiemstra, Peter H. Schalk (1980): Biosystematic studies of the Rumex acetosella complex (Polygonaceae). IV. Pollen morphology and the possibilities of identification of cytotypes in pollen analysis. – Phyton, Annales Rei Botanicae, Horn – 20_3_4: 307 - 323.