Barber, Janet C. (2000). "Evolution of Endemic Sideritis (Lamiaceae) in Macaronesia: Insights from a Chloroplast DNA Restriction Site Analysis". Systematic Botany. 25 (4): 633–647. doi:10.2307/2666725. JSTOR2666725. S2CID86223380.
Figuerola, R.; Stübing, G.; Peris, J. B. (1991). "Nomenclature and Typification of Sideritis angustifolia and S. tragoriganum (Lamiaceae, Spain)". Taxon. 40 (1): 123–9. doi:10.2307/1222936. JSTOR1222936.
Barber, Janet C. (2000). "Evolution of Endemic Sideritis (Lamiaceae) in Macaronesia: Insights from a Chloroplast DNA Restriction Site Analysis". Systematic Botany. 25 (4): 633–647. doi:10.2307/2666725. JSTOR2666725. S2CID86223380.
Figuerola, R.; Stübing, G.; Peris, J. B. (1991). "Nomenclature and Typification of Sideritis angustifolia and S. tragoriganum (Lamiaceae, Spain)". Taxon. 40 (1): 123–9. doi:10.2307/1222936. JSTOR1222936.
Barber, Janet C. (2000). "Evolution of Endemic Sideritis (Lamiaceae) in Macaronesia: Insights from a Chloroplast DNA Restriction Site Analysis". Systematic Botany. 25 (4): 633–647. doi:10.2307/2666725. JSTOR2666725. S2CID86223380.