Taylor, Nigel; Zappi, Daniela (2018). "Additions and corrections to 'Cacti of Eastern Brazil'". Bradleya. 36 (36). British Cactus and Succulent Society: 2–21. doi:10.25223/brad.n36.2018.a2. ISSN0265-086X.
Taylor, Nigel; Zappi, Daniela (2018). "Additions and corrections to 'Cacti of Eastern Brazil'". Bradleya. 36 (36). British Cactus and Succulent Society: 2–21. doi:10.25223/brad.n36.2018.a2. ISSN0265-086X.