1. . Artemisia, Medicinal and Aromatic Plants?Industrial Profiles, (ed.). Taylor and Francis, London, 2002.
2. . Ilustrierte Flora von Mittel Europa Bd. IV, Part 4. Paul Parey Verlag: Berlin, 1987; 644- 645.
3. . Flora Europaea, (eds), Vol. 4. Cambridge University Press: Cambridge, 1976; 178.
4. . Our Medicinal Plants Part 1. Nauka i Izkustvo: Sofia, 1972; 152.