The most recent editions of Emily Dickinson's poetry and letters remain under copyright. These editions--The Poems of Emily Dickinson, ed. R. W. Franklin, 1998; The Poems of Emily Dickinson, ed. Thomas Johnson, 1955; and The Letters of Emily Dickinson, ed. Thomas Johnson, 1958--are considered the most authoritative and the best available editions in print of her work. Harvard University Press administers the copyright to all editions. Information about applying for permissions can be found at Harvard University Press Permissions.
Early editions of Dickinson's work are now in the public domain. These editions include those edited by Mabel Loomis Todd and Thomas Wentworth Higginson in the 1890s, as well as some of Martha Dickinson Bianchi's editions. In order to avoid copyright problems, it is best to check with Harvard University Press to find out whether the text you wish to cite remains under copyright. For a complete list of the major posthumous publications of Dickinson's work, go to Major Editions of Dickinson's Writings.