Original: Ernst Heinrich Philipp August Haeckel (February 16, 1834 – August 9, 1919),"Ernst Haeckel — Britannica Concise" (biography), Encyclopædia Britannica Concise, 2006, Concise.
Simplified: Ernst Heinrich Philipp August Haeckel (February 16, 1834 — August 9, 1919),"Ernst Haeckel - Britannica Concise" (biography), Encyclopædia Britannica Concise, 2006, Concise.