S. PÉREZ-ESPONA, F. SALES, I. HEDGE, and M. MÖLLER, “PHYLOGENY AND SPECIES RELATIONSHIPS IN JASIONE (CAMPANULACEAE) WITH EMPHASIS ON THE ‘MONTANA-COMPLEX’”, Edinburgh J. Bot., vol. 62, no. 1-2, pp. 29–51, Feb. 2006, doi: 10.1017/S0960428606000047.