The Golden Oldies series of the journal General Relativity and Gravitation reprints important papers in general relativity theory that were published 30 or more years ago and are either hard to get hold of, or were originally printed in a language other than English. They play a key part in making these important papers readily accessible today, in the language that has now become the lingua franca of scientific publication. The value of this reprinting is enhanced by an accompanying editorial note for each paper, which briefly explains the significance of the work and where it has subsequently led to, together with a biographical note about the author or authors.

This volume presents a selection of 14 rarities among the Golden Oldies grouped in the three categories "Basic results in differential geometry and general relativity," "Discussion of physical effects" and "Basic exact solutions and their interpretation." Researchers in the field will appreciate having these important papers collected in one book for the first time.

Reprinted from the journal General Relativity and Gravitation.