Link on online library
https://ebooks.adelaide.edu.au/s/shelley/mary/ You can read there: History of Six Weeks' Tour through a Part of France, Switzerland, Germany, and Holland,with Letters Descriptive of a Sail round the Lake of Geneva, and of the Glaciers of Chamouni [1817] Frankenstein; or, The Modern Prometheus [1818, 1831] Mathilda [1819] Valperga; or, The Life and Adventures of Castruccio, Prince of Lucca [1823] The Last Man [1826] Lodore [1835] Falkner [1837] The Poetical Works of Percy Bysshe Shelley [1839] Proserpine & Midas: two unpublished Mythological Dramas / edited with an introduction by A. Koszul