Typically, Eliot first published his poems individually in periodicals or in small books or pamphlets, and then collected them in books. His first collection was Prufrock and Other Observations (1917). In 1920, he published more poems in Ara Vos Prec (London) and Poems: 1920 (New York). These had the same poems (in a different order) except that "Ode" in the British edition was replaced with "Hysteria" in the American edition. In 1925, he collected The Waste Land and the poems in Prufrock and Poems into one volume and added The Hollow Men to form Poems: 1909–1925 . From then on, he updated this work as Collected Poems . Exceptions are Old Possum's Book of Practical Cats (1939), a collection of light verse; Poems Written in Early Youth , posthumously published in 1967 and consisting mainly of poems published between 1907 and 1910 in The Harvard Advocate , and Inventions of the March Hare: Poems 1909–1917 , material Eliot never intended to have published, which appeared posthumously in 1997.