 The fourth edition, published by "Editorial Porrúa" in Mexico in 1969 with an Introduction by Miguel León-Portilla, was another facsimile reprint of the second edition, but, this time, employing a magnificent large paper exemplar formerly owned by the Mexican historian Joaquín García Icazbalceta.The fifth edition (substantively, the third, critical edition) was published by the "Instituto de Investigaciones Históricas" (IIH), a research institute of the National Autonomous University of Mexico (UNAM), in seven volumes between 1975 and 1983.A research team was assembled under the direction of Miguel León-Portilla with the task of establishing the text (without, however, the benefit of the original manuscript, which could not be located) and of publishing it in six volumes, with (among other materials) analytic indices tracking Torquemada's sources.