John J O'Connor and Edmund F Robertson, MacTutor History of Mathematics archive (University of St Andrews, 2005).
jˈohn jˈiː okˈonnor ˈand ˈedmund ˈæf robˈertson, mˈak tˈutor hɪstˈory ˈof mˌathemˈatɪks arkhˈive ˌunɪversˈity ˈof ˌæstˈeː ˈandrevs, kˈaksi tˌuhatːa vˈiːsi.