Vienna, Österreichen Nationalbibliothek MS. 11339 [Med. 162.] 49 folios. Paper. Quarto. 17th Century. 1. f1-33v Wolfgango Sigismundo Unverzagt barone de Retzer, 'Specchio d'alchimia'. [Letter to Emperor Ferdinand III.] 2. f34-46v [By the same author] Trattato secondo, nel quale viene dichiarato li più occulti arcani della madre natura. 3. f47-49 [By the same author. A letter in Italian to the Emperor containing two experiments about the method of making the stone of Saturn.]