(1)
VALANT-VETSCHERA, K. M.; KÄSTNER, A. CHARACTER ANALYSIS IN ACHILLEA SECT. SANTOLINOIDEA (COMPOSITAE–ANTHEMIDEAE): PART I. LEAF AND FLORAL MORPHOLOGY. Edinburgh J. Bot. 2000, 57 (2), 189-208. https://doi.org/10.1017/S0960428600000135.