Russian mathematician Sergey Shpilkin at the "Navalny LIVE" YouTube channel's program Oblako (The Cloud), ep. 22
YouTube channel "<a rel="nofollow" class="external text" href="https://www.youtube.com/channel/UCgxTPTFbIbCWfTR9I2-5SeQ">Навальный LIVE</a>"
CC BY 3.0
"<a rel="nofollow" class="external text" href="https://www.youtube.com/watch?v=zwY0Vx9ie5g">Математика выборов. Гость — независимый эксперт Сергей Шпилькин</a>" (frame grab, 0:00:36)