 Zane Grey's Western novel, Riders of the Purple Sage, was released in 1912. Edgar Rice Burroughs' story of a man raised by apes was released in 1914, titled Tarzan of the Apes. Margaret Singer published the pamphlet Family Limitation in 1914, which explained how to prevent pregnancy. William Williams formed the core of the Imagist movement with his book of poetry, Spring in All, in 1923.