Leppanen co-edited with Dickran Tashjian and contributed two essays for the multi-media publication Joseph Cornell's Manual of Marvels (Thames & Hudson Press, 2012). Joseph Cornell's Manual of Marvels is based on Cornell's complex and pioneering book-object Untitled (Journal d'Agriculture Pratique) (c.1930s-40s), a French agricultural yearbook dating from 1911, which Cornell altered through cut-outs, drawings, collaged material, and origami. The project includes a volume of scholarly essays (by Dickran Tashjian, Dawn Ades, and Leppanen-Guerra), partial facsimile, and interactive CD-ROM digitally reproducing the pages of the book along with commentary – all packed in a wood-grain box.
