Pospielov, S., et al. “Formation of Pale Purple Coneflower (Echinacea Pallida (Nutt.) Nutt.) Seed Productivity in the Conditions of the Left-Bank Forest-Steppe of Ukraine”. Scientific Progress & Innovations, vol. 28, no. 1, Mar. 2025, pp. 68-74, doi:10.31210/spi2025.28.01.12.