- "The Secret Life of Leonardo da Vinci" (1948)
- "The Galileans" (1950)
- "The Golden Madonna" (1951)
- "The Darkening Glass" (1953)
- "The Pilgrim" (1954)
- "The Bride of Nazareth" (1955)
- "The Rebel Bride" (1957)
- "The Scarlet Sword" (1959)
- "The Nazarene" (1961)
- "The Galilean" (1963)
- "The Judas Testament" (1965)
- "The Crucifixion" (1967)
- "The Resurrection" (1969)
- "The Ascension" (1971)
- "The Last Judgement" (1973)
Non-Fiction:
- "Leonardo's Workshop" (1960)
- "Leonardo: The Artist" (1961)
- "Leonardo: The Scientist" (1962)
- "Leonardo: The Man" (1963)
- "The Age of Leonardo" (1965)
- "Leonardo: A Biography" (1969)
- "The Life of Leonardo" (1972)
- "The Complete Works of Leonardo da Vinci" (1974)
- "The Mind of Leonardo" (1976)
- "The World of Leonardo" (1978)
- "The Legacy of Leonardo" (1980)
- "Leonardo: The Greatest Genius" (1982)
- "The Genius of Leonardo" (1984)
- "Leonardo: The Master of Art and Science" (1986)