A decade after Stanley Ross and his associates at the Colegio de México began assembling materials for a book on the periodical sources of Mexican contemporary history (that is, since 1910), the long-awaited second volume appears. (The first volume, published in 1965, was reviewed in HAHR, August 1967.) Sections of this volume deal with the election of 1920, the administrations of Obregón, Calles, and Cárdenas, and general aspects of Revolutionary history such as the Church, education, foreign relations, finances, etc. The two volumes list 27,719 articles, each with a line or two summarizing the contents. There is an author’s index and, more important, very useful indices of per sons, places, and institutions. Of special note is an index of cross references to provide instant bibliographies for students of the Revolution. Now if we could only persuade the Colegio to put a group to work assembling sources for the period 1940-1960!