Product Details: 4 softcovers, all unused; study guide 1 is for books 1-4 about Aylward, Liddell, Saint, Muller; Volume 2 is for Books 5-8 about Carmichael, ten Boom, Slessor, Carey; Volume 3 about books 9-12 about Greene, Livingstone, Judson, Taylor; Volume 4 for books 13-16 about Elliot, Goforth, Townsend, Moon