The image shows Lucifer Morningstar, Beelzebub, Azazel and Morpheus before the hosts of Hell in Neil Gaiman's The Sandman: Preludes And Nocturnes (New York, 1989). This scene was inspired by a similar gathering of the Hellish host in Magic Inc. by Robert Heinlein. Poul Anderson, inspired by Magic Inc., described an expedition to Hell in Operation Chaos.
Late at night, I escape from the non-visual medium of prose fiction into either TV or graphic fiction although unfortunately Poul Anderson's works have not been adapted into these media yet. Because Anderson has accustomed me to always checking the meanings of Latin quotations, I googled the Liber Fulvarum Paginarum (p. 36) (here) and discovered that this fictional yellow book is referenced by both Neil Gaiman and Terry Pratchett. I think we can be confident that there is a copy on the shelf in the Old Phoenix.