Woytek 2022a, p. 379 and 381: "Among the momentous manuscript volumes in Eckhel’s hand preserved in Vienna, three books in modest, but durable half-leather bindings, whose boards are covered in 18th century monochrome (red or brown) marbled paper, stand out because of their in-folio format (archives nos. 79–81). Stylistically, their bindings are very similar to that of the quarto notebook no. 7, described above. These three folio notebooks – highly diverse in character between themselves – are dedicated to three different classes of ancient coins. All are characterised by more or less generous right- or left-hand margins left blank for additions and corrections; this is a feature they share with the quarto notebooks nos. 5–7, incidentally. ... The folio notebook no. 81, by contrast, is extremely heterogeneous in content: it comprises an alphabetical listing of Roman emperors, empresses and usurpers, from Achilleus to Zoe (pp. 1–229), whose names were probably not written by Eckhel himself. He made minor notes – mostly giving bibliographical references – underneath some of these underlined headers, but many spots are left blank. This list is followed, on pp. 231–236, by a text and various notes on fake Roman imperial coins that provided the material for the “praefatio” of volume 6 of the Doctrina. Furthermore, the manuscript contains, among other things, a list of questions about coins from international collections that had come up in the course of Eckhel’s work, ordered by the cities or countries where the respective coins were kept (Florence, Paris, Naples, England etc., pp. 244–252), as well as a few pages with excerpts from books on ancient architecture published in the 1760s (pp. 253–255)".
