Shyshka, Roman, y Maxym Tkalych. «The World in 2020: What Are the Threats to Humanity?». Revista Amazonia Investiga 9, no. 26 (febrero 21, 2020): 3–5. Accedido febrero 28, 2026. https://www.amazoniainvestiga.info/index.php/amazonia/article/view/1132.