‎"EINSTEIN, ALBERT und W. MAYER.‎
‎Systematische Untersuchung über kompatible Feldgleichungen, welche in einem Riemannschen Raume mit Fernparallelismus gesetz werden können.‎

‎Berlin, Gruyter & Co., 1931. 4to. Orig. printed orange wrappers. Offprint/Sonderausgabe aus Sitzungsberichten....pp. (1)-11. Fine fresh copy.‎

Reference : 28368

‎First edition of the rare Offprint with separate title and separate pagination. Se Weil No. 180, where this is not mentioned. - Mayer came to America in 1933, and about him as his collaborator, Einstein said ""It is he who produced all my calculations, his skill is fantastic, You know.""The early Offprints from ""Sitzungsberichten..."" are called ""Sonderabdruck"" up to Weil No.165 (including this). From Weil 166 they are called ""Sonderausgabe..."". - Before 161 (up to 160) the Offprints do not have separate title and pagination (the pagination follows the numbering in the periodical). From 166 the Offprint has both separate printed title and pagination. - ( So Weil Nos 161-165 is still ""Abdruck"", but with separate title and pagination). These facts are not mentioned in the bibliographies.‎