Confessions of the Mad Monk Clithanus

Latin, by Clithanus, 400 (1674)
A retreading of material Clithanus gleaned from reading the Necronomicon. Contains lengthy treatise on sigils of protection and the spawn of Cthulhu. Copies are maintained at the Field Museum of Chicago, the British Museum, and the Union Theological Seminary in Manhattan.

Location
Field Museum of Chicago
the British Museum
the Union Theological Seminary in Manhattan