Lilies of the Field, William Edmund Barrett.

. The enchanting story of two unlikely friends, a black ex-GI and the head of a group of German nuns, The Lilies of the Field tells the story of their impossible dream—to build a chapel in the desert.

William E. Barrett (1900-1986) wrote numerous novels, short stories and articles. His novel, The Left Hand of God, was translated into ten different languages and was made into a movie, starring Humphrey Bogart. The Lilies of the Field was made into a movie starring Sidney Poitier in 1963. Barrett's work reflects the dilemmas of his society through interpersonal relationships and religious and ethical decisions made by his characters. His writings are representative of the needs of the age, and had great impact upon thousands of readers. The collection consists of copies of Barrett's published works, original manuscripts and revisions, research materials, and correspondence relating to his writings. The collection spans the years 1926-1975, and also includes material concerning the movie adaptations of his novels.

Another book I haven't read, its from the list compiled by Boris; hence the error for which I must apologise.