Cambridge, Trinity College MS. O.4.20. 100 folios. Paper. 12.5x8.25. In autograph of Dr John Dee. 16th Century. Catalogus Librorum Bibliothecae (externae) Mortlacensis D. Joh. Dee, ao. 1583, 6 Sept. [MS Harley 1879, is another autograph copy, and in MSS. Add. 35213 is another catalogue, perhaps of an earlier date, also written by Dee].