Book excerpt: A translation of selected non-English texts included in Volume 13 is available in paperback. Since this supplementary paperback includes only select portions of Volume 13, it is not recommended for purchase without the main volume. Every document in The Collected Papers of Albert Einstein appears in the language in which it was written, and this supplementary paperback volume presents the English translations of select portions of non-English materials in Volume 13. This translation does not include notes or annotation of the documentary volume and is not intended for use without the original language documentary edition which provides the extensive editorial commentary necessary for a full historical and scientific understanding of the documents.