Gratzer, G. The congruences of a finite lattice: A proof-by-picture approach.
Lua i Stíl Chicago (17ú heag.)Gratzer, George. The Congruences of a Finite Lattice: A Proof-by-picture Approach.
Lua MLA (8ú heag.)Gratzer, George. The Congruences of a Finite Lattice: A Proof-by-picture Approach.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.