When time travelling Daleks failed to effectively control the Roman emperor Caligula, the Elite Guard Dalek abandoned the mission whilst noting that there were other nexus points in human history. (COMIC: Empire of the Daleks [+]Mark Wright, Dalek: The Astounding Untold History of the Greatest Enemies of the Universe (Dalek: The Astounding Untold History of the Greatest Enemies of the Universe, 2017).)
Nexus points existed on other planets too, such as Bav and Teth, which were also attacked by the Daleks. (PROSE: The Dalek Problem [+]The Doctor Who Role Playing Game supplements (FASA, 1986).)
The Seventh Doctor identified the Wenley Moor Affair as a crucial nexus-point in Earth's time stream from which a countless number of futures could be claimed resulting in near-endless divergent realities. (COMIC: Final Genesis [+]Warwick Gray, DWM Comics (Marvel Comics, 1993).)