of which had sold considerably more than 30,000 copies.) After Christie's authorship of the first four Westmacott novels was revealed by a journalist in 1949, she wrote two more, the last in 1956. The other Westmacott titles are: Unfinished Portrait (1934), Absent in the Spring (1944), The Rose and the Yew Tree (1948), A Daughter's a Daughter (1952), and The Burden (1956). Non-fiction works Christie published few non-fiction works. Come, Tell Me How You Live, about working on an archaeological dig, was drawn from her life with Mallowan. The Grand Tour: Around the World with the Queen of Mystery is a collection of correspondence from her 1922 Grand Tour of the British empire, including South Africa, Australia, New Zealand, and Canada. Agatha Christie: An Autobiography was published posthumously in 1977 and adjudged the Best Critical/Biographical Work at the 1978 Edgar Awards. Titles Many of Christie's works from 1940 onward have titles drawn from literature, with the original context of the title typically printed as an epigraph. The inspirations for some of Christie's titles include: William Shakespeare's works: Sad Cypress, By the Pricking of My Thumbs, There is a Tide..., Absent in the Spring, and The Mousetrap, for example. Osborne notes that "Shakespeare is the writer most quoted in the works of Agatha Christie"; The Bible: Evil Under the Sun, The Burden, and The Pale Horse; Other works of literature: The Mirror Crack'd from Side to Side (from Tennyson's "The Lady of Shalott"), The Moving Finger (from Edward FitzGerald's translation of the Rubáiyát of Omar Khayyám), The Rose and the Yew Tree (from T. S. Eliot's Four Quartets), Postern of Fate (from James Elroy Flecker's "Gates of Damascus"), Endless Night (from William Blake's "Auguries of Innocence"), N or M? (from the Book of Common Prayer), and Come, Tell Me How You Live (from Lewis Carroll's Through the Looking-Glass). Christie biographer Gillian Gill said, "Christie's writing has the sparseness, the directness, the narrative pace, and the universal appeal of the fairy story, and it is perhaps as modern fairy stories for grown-up children that Christie's novels succeed." Reflecting a juxtaposition of innocence and horror, numerous Christie titles were drawn from well-known children's nursery rhymes: And Then There Were None (from "Ten Little Niggers"), One, Two, Buckle My Shoe (from "One, Two, Buckle My Shoe"), Five Little Pigs (from "This Little Piggy"), Crooked House (from "There Was a Crooked Man"), A Pocket Full