Kaplan Z. (2004): Tragopogon L. – kozí brada. – In: Slavík B., Štěpánková J. & Štěpánek J. (eds), Květena České republiky 7, p. 733–743, Academia, Praha.
The texts and drawings from the Flora of the Czech Republic are published with the consent of the Academia publishing house and the authors of the drawings. The quality of reproduced illustrations in the scanned version of the Flora of the Czech Republic does not reach the quality of original botanical pen drawings prepared by the artists.