Analysis of information sources in references of the Wikipedia article "Ernst Haeckel" in English language version.
On 16 February 1834 a son was born to Charlotte and Carl Gottlob Haeckel in Kanal 24a (later Yorkstrasse 7), Potsdam, Prussia. His name was Ernst Heinrich Phillip August, and he was destined to become one of the most influential and controversial thinkers of his time.
testimony of Emil Felden in Was wir Ernst Haeckel Verdanken, vol. ii, p. 125.
PROFESSOR Ernst Haeckel's celebration of his 80th birthday, ...on this occasion we note a work of two stately volumes, entitled Was wir Ernst Haeckel verdanken, edited at the request of the German Monistenbund by Heinrich Schmidt of Jena. (Image of p. 385 at Google Books)
There is no doubt that the course and character of the feared "European War"...will become the first world war in the full sense of the word. Indianapolis Star, 20 September 1914
testimony of Emil Felden in Was wir Ernst Haeckel Verdanken, vol. ii, p. 125.