1. The Congruences of a Finite Lattice : a "Proof-by-Picture" Approach /: a "Proof-by-Picture" Approach. (2016) Other Names: Gratzer, George A Record Type: Book Extent: 1 online resource (XXXIV, 346 pages), 159 illustrations View Content: Available online (eLD content is only available in our Reading Rooms) ↗