ジョン・スノウによるコレラ死亡者の分布図（ジョン・スノー - Map of the book "On the Mode of Communication of Cholera" by John Snow, originally published in 1854 by C.F. Cheffins, Lith, Southhampton Buildings, London, England.The uploaded images is a digitally enhanced version found on the UCLA Department of Epidemiology website., パブリック・ドメイン, <a href="https://commons.wikimedia.org/w/index.php?curid=2278605" class="n" target="_blank">https://commons.wikimedia.org/w/index.php?curid=2278605</a>による）

ジョン・スノウによるコレラ死亡者の分布図（ジョン・スノー - Map of the book "On the Mode of Communication of Cholera" by John Snow, originally published in 1854 by C.F. Cheffins, Lith, Southhampton Buildings, London, England.The uploaded images is a digitally enhanced version found on the UCLA Department of Epidemiology website., パブリック・ドメイン, https://commons.wikimedia.org/w/index.php?curid=2278605による）