FERRER-GALLEGO, P. P., R. Roselló, E. Laguna, J. Gómez, and J. B. Peris. “Typification of Two Linnaean Names: Centaurea Aspera and Centaurea Isnardii (Asteraceae)”. Phytotaxa, vol. 183, no. 2, Oct. 2014, pp. 114–118, doi:10.11646/phytotaxa.183.2.4.