EINSTEIN, Albert. Die Grundlage der allgemeinen Relativitätstheorie. Leipzig: Barth, 1916. 8o. Original printed wrappers (some chipping and splitting to edges and spine). First separate printing. Offprint from: Annalen der Physik, Volume 49, no. 7. With Omnitypie-Ges. imprint on verso of title page and Metzger and Wittig imprint on back wrapper. Weil 80a.