- "Leonardo da Vincis hemmelige liv" (1948)
- "Galilæerne" (1950)
- "Den Gyldne Madonna" (1951)
- "The Darkening Glass" (1953)
- "Pilgrimmen" (1954)
- "Bruden fra Nazareth" (1955)
- "The Rebel Bride" (1957)
- "The Scarlet Sword" (1959)
- "Nazaræeren" (1961)
- "The Galilean" (1963)
- "Judas Testamentet" (1965)
- "Korsfæstelsen" (1967)
- "Opstandelsen" (1969)
- "The Ascension" (1971)
- "Den sidste dom" (1973)
Faglitteratur:
- "Leonardos værksted" (1960)
- "Leonardo:Kunstneren" (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)
- "Arven efter Leonardo" (1980)
- "Leonardo:The Greatest Genius" (1982)
- "The Genius of Leonardo" (1984)
- "Leonardo:Master of Art and Science" (1986)