Homoerotic poetry is a genre of poetry implicitly dealing with same-sex romantic or sexual interaction. The male-male erotic tradition encompasses poems by major poets such as Pindar, Theognis of Megara, Anacreon, Catullus, Virgil, Martial, Abu Nuwas, Michelangelo, Walt Whitman, Federico García Lorca, W. H. Auden, Fernando Pessoa and Allen Ginsberg. In the female-female tradition, authors may include those such as Sappho, "Michael Field", "Marie-Madeleine" and Maureen Duffy. Other poets wrote poems and letters with homoerotic overtones toward individuals, such as Emily Dickinson to her sister-in-law Susan Huntington Gilbert.