The social network of Leonard Cohen. The vertex are {"Leonard Cohen", "Nico", "Andy Warhol", "John Cale", "Madonna (entertainer)", "Jeff Buckley", "Jennifer Warnes", "John Mellencamp", "Joni Mitchell", "Ray Martin (television presenter)", "Lana Del Rey", "Kurt Cobain", "Marianne Ihlen", "Joan Baez", "Herbie Hancock", "Walt Whitman", "Julie Christensen", "Perla Batalla"}