Additions
In 1548 Gesner followed with a companion work to Bibliotheca universalis, a large folio, Pandectarum sive Partitionum universalium Conradi Gesneri (Pandectae). This contained thirty thousand topical entries. Each of these entries were cross-referenced to the appropriate author and book, arranged under headings and sub-headings, which were associated with various branches of learning.
The Pandects had nineteen sections, each devoted to a scholarly discipline and contained dedications to the best scholar printers of Gesner's time. He listed their publications and accomplishments. Gesner made full use of any publishers' catalogues and booksellers' lists which were available in the 16th century that were printed when he was doing his research. Hans Fischer in his book Conrad Gesner (1516–1565) as Bibliographer and Encyclopaedists points out that Gesner made use of printed catalogues supplied by firms like Aldus Manutius of Venice and Henri Estienne of Paris.
Read more about this topic: Bibliotheca Universalis