Albert Einstein / Max Planck u.a. (Königlich Preussische Akademie der Wissenschaften) - Original First Printing on Gravitational Waves (Sitzungsberichte Berlin) - 1916

Proceedings of the Royal Prussian Academy of Sciences. Year 1916, First Half-Volume: January to June. Berlin, Publisher of the Royal Academy of Sciences, in commission at Georg Reimer, 1916. The half-volume comprises items I–XXIV and, according to the title page, contains two plates. The contributions cover various scientific disciplines.
Included is Albert Einstein's “Approximate Integration of the Field Equations of Gravitation” on pages 688–696. The paper appeared in 1916 and deals with Einstein's work on the theory of gravitation. The volume is German-language.