📚 **The Collected Papers Of Albert Einstein**
Volume One: https://archive.org/details/the-collected-papers-of-albert-einstein-vol-l/.
Volume Two: https://archive.org/details/the-collected-papers-of-albert-einstein-vol-2-1900-1909.
Volume Three: https://archive.org/details/the-collected-papers-of-albert-einsten-volume-3-the-swiss-year-1909-1911.
Volume Six: https://archive.org/details/the-collected-papers-of-albert-einstein-vol.-6-the-berlin-years-writings-1914-1917.