* "Manden fra skyerne" (1937)
* "Death in Air" (1938)
* "Flygende farver" (1940)
* "Dobbelteksponering" (1941)
* "Det gule tørklæde" (1942)
* "The White Rose of Athens" (1943)
* "Den sorte død" (1944)
* "The Scarlet Angel" (1945)
* "Den grønne maske" (1946)
* "Det blå tog" (1947)
* "Den lilla sky" (1948)
* "Den røde død" (1949)
* "The Brown Veil" (1950)
* "The Grey Mist" (1951)
* "Den blege tiger" (1952)
* "The Dark Room" (1953)
* "Sølvdolken" (1954)
* "Den gyldne slange" (1955)
* "The Ivory Madonna" (1956)
* "Jaderingen" (1957)
* "The Scarlet Feather" (1958)
* "The Azure Flame" (1959)
* "The Emerald Chalice" (1960)
* "The Amber Amulet" (1961)
* "The Ruby Key" (1962)
* "Perlearmbåndet" (1963)
* "The Silver Skull" (1964)
* "Den gyldne dolk" (1965)
* "The Ivory Idol" (1966)
* "Jademasken" (1967)
* "The Scarlet Claw" (1968)
* "Den blå diamant" (1969)
* "Den grønne tiger" (1970)
* "The Purple Heart" (1971)
* "Den brune panter" (1972)
* "The Grey Falcon" (1973)
* "Den blege panter" (1974)
* "The Pale Fox" (1975)
* "Guldulven" (1976)
* "Elfenbensuglen" (1977)
* "The Jade Tiger" (1978)
* "Den røde død" (1979)
* "Den røde tiger" (1980)
* "Den røde rose" (1981)
* "The Red Fox" (1982)
* "Den røde falk" (1983)
* "Den røde ulv" (1984)
* "Den røde panter" (1985)
* "Den røde ugle" (1986)
* "Den røde slange" (1987)
* "Den røde due" (1988)
* "Den røde løve" (1989)
* "Den røde ørn" (1990)
* "Den røde hest" (1991)
* "Den røde bjørn" (1992)
* "Den røde drage" (1993)
* "The Red Phoenix" (1994)
* "Den røde enhjørning" (1995)
* "The Red Griffin" (1996)
* "Den røde sfinks" (1997)
* "The Red Octopus" (1998)
* "Den røde krabbe" (1999)
* "Den røde haj" (2000)
* "Den røde skorpion" (2001)
* "Den røde edderkop" (2002)
* "Den røde bille" (2003)
* "Den røde tusindben" (2004)
* "Den røde myre" (2005)
* "Den røde hveps" (2006)
* "Den røde bi" (2007)
* "Den røde sommerfugl" (2008)
* "Den røde møl" (2009)
* "The Red Scarab" (2010)
Faglitteratur:
* "Spionen bag linjerne" (1939)
* "Den store spionmyte" (1940)
* "The Secret Services of Europe" (1941)
* "Spionen fra Mars" (1942)
* "Spionen i det næste rum" (1943)
* "Krigen bag fronten" (1944)
* "Hemmeligheden bag Hitlers krig" (1945)
* "The Battle of the Brains" (1946)
* "Den usynlige krig" (1947)
* "Det store spioneventyr" (1948)
* "The Master Spy" (1949)
* "The Spycatcher" (1950)
* "The Spy Network" (1951)
* "Spionfælden" (1952)
* "The Spy Killer" (1953)
* "Spionjægeren" (1954)
* "The Spy Chaser" (1955)
* "The Spy Catcher" (1956)
* "The Spy Smasher" (1957)
* "The Spy Breaker" (1958)
* "The Spy Tamer" (1959)
* "The Spy Defier" (1960)
* "The Spy Challenger" (1961)
* "The Spy Traitor" (1962)
* "The Spy Vanisher" (1963)
* "The Spy Assassin" (1964)
* "The Spy Saboteur" (1965)
* "The Spy Destroyer" (1966)
* "The Spy Dictator" (1967)
* "The Spy Conqueror" (1968)
* "The Spy Eliminator" (1969)
* "The Spy Annihilator" (1970)
* "The Spy Exterminator" (1971)
* "The Spy Decimator" (1972)
* "The Spy Vanquisher" (1973)
* "The Spy Obliterator" (1974)
* "The Spy Destroyer" (1975)
* "The Spy Eliminator" (1976)
* "The Spy Annihilator" (1977)
* "The Spy Exterminator" (1978)
* "The Spy Decimator" (1979)
* "The Spy Vanquisher" (1980)
* "The Spy Obliterator" (1981)
* "The Spy Destroyer" (1982)
* "The Spy Eliminator" (1983)
* "The Spy Annihilator" (1984)
* "The Spy Exterminator" (1985)
* "The Spy Decimator" (1986)
* "The Spy Vanquisher" (1987)
* "The Spy Obliterator" (1988)
* "The Spy Destroyer" (1989)
* "The Spy Eliminator" (1990)
* "The Spy Annihilator" (1991)
* "The Spy Exterminator" (1992)
* "The Spy Decimator" (1993)
* "The Spy Vanquisher" (1994)
* "The Spy Obliterator" (1995)
* "The Spy Destroyer" (1996)
* "The Spy Eliminator" (1997)
* "The Spy Annihilator" (1998)
* "The Spy Exterminator" (1999)
* "The Spy Decimator" (2000)
* "The Spy Vanquisher" (2001)
* "The Spy Obliterator" (2002)
* "The Spy Destroyer" (2003)
* "The Spy Eliminator" (2004)
* "The Spy Annihilator" (2005)
* "The Spy Exterminator" (2006)
* "The Spy Decimator" (2007)
* "The Spy Vanquisher" (2008)
* "The Spy Obliterator" (2009)
* "The Spy Destroyer" (2010)