- 'The Searchers' (1960)
- 'The Big Game' (1962)
- 'Kæmpernes kamp' (1964)
- 'The Great Battle of the Apes' (1965)
- 'Landet, som tiden glemte' (1966)
- 'The People That Time Forgot' (1967)
- "Out of Time's Abyss" (1968)
- Beyond Time's End (1969)
- 'Castle Death' (1970)
- 'King Cobra' (1971)
- 'Den fortabte verden' (1972)
- Plague City (1973)
- 'Tarzans tilbagevenden' (1974)
- 'The Warlord of Mars' (1975)
- 'Prinsessen af Mars' (1976)
- "John Carter and the Giant of Mars" (1977)
- 'The Gods of Mars' (1978)
- 'Thuvia, Maid of Mars' (1979)
- 'Tarnsman of Gor' (1980)
- Assassin of Gor (1981)
- `Slave Girl of Gor` (1982)
- 'Rogue of Gor' (1983)
- "Captive of Gor" (1984)
- 'Raiders of Gor' (1985)
- 'Fight for Gor' (1986)
- `Tribesmen of Gor` (1987)
- 'Outlaw of Gor' (1988)
- `Savages of Gor` (1989)
- 'Hunter of Gor' (1990)
- 'Killer of Gor' (1991)
- `Destroyer of Gor` (1992)
- 'Beast Master of Gor' (1993)
- 'Slave Lord of Gor' (1994)
- 'Valdor, Erobreren af Gor' (1995)
- 'Troldmandens konge af Gor' (1996)
- `Caballus, hesteherren af Gor` (1997)
- `The Heirs of Gor` (1998)
- `Tarl Cabbot, Ruler of Gor` (1999)
- 'Lord of the Pram' (2000)
- 'Iskongen' (2001)
- 'Den fortabte legion' (2002)
- 'Nordens jernulve' (2003)
- 'The Last of the Celts' (2004)
- `Løvens stolthed` (2005)
- `Ørnens flugt` (2006)
- `Ulvens hævn` (2007)
- `The Bear's Fury` (2008)
- `The Dragon's Fire` (2009)
- `Slangens skygge` (2010)
- `Ederkoppens web` (2011)
- `Skorpionens brod` (2012)
- `Tigerens Klo` (2013)
- `Hajens tænder` (2014)
- `Krokodillens kæber` (2015)
- `Elefantens snabel` (2016)
- `The Hippo's Charge` (2017)
- `Næsehornets horn` (2018)
- `The Buffalo's Stampede` (2019)
- `Løvens brøl` (2020)
Noveller:
- "Dødsmasken" (1960)
- "Terrorens tempel" (1961)
- "The Eye of the Idol" (1962)
- "Mumiens forbandelse" (1963)
- "The Man-Eaters of Tsavo" (1964)
- "Sneens leopard" (1965)
- "Den hvide død" (1966)
- "The Ghost Tiger" (1967)
- "The Giant Squid" (1968)
- "The Loch Ness Monster" (1969)
- "Den afskyelige snemand" (1970)
- "The Thunderbird" (1971)
- "The Quetzalcoatl" (1972)
- "Den store slange" (1973)
- "The Vampire Bat" (1974)
- "Varulven" (1975)
- "The Zombie" (1976)
- "Mumien" (1977)
- "The Ghost" (1978)
- "Dæmonen" (1979)
- "Heksen" (1980)
- "Troldmanden" (1981)
- "The Sorcerer" (1982)
- "The Necromancer" (1983)
- "The Warlock" (1984)
- "The Enchanter" (1985)
- "Trylleren" (1986)
- "The Illusionist" (1987)
- "The Trickster" (1988)
- "The Jester" (1989)
- "The Fool" (1990)
- "Knægten" (1991)
- "Ridderen" (1992)
- "The Rook" (1993)
- "Biskoppen" (1994)
- "Dronningen" (1995)
- "Kongen" (1996)
- "Kejseren" (1997)
- "Kejserinden" (1998)
- "Paven" (1999)
- "Kardinalen" (2000)
- "Biskoppen" (2001)
- "Præsten" (2002)
- "Diakonen" (2003)
- "Munken" (2004)
- "Nonnen" (2005)
- "The Saint" (2006)
- "Synderen" (2007)
- "Djævelen" (2008)
- "The Heretic" (2009)
- "Den frafaldne" (2010)
- "The Blasphemer" (2011)
- "Ateisten" (2012)
- "The Agnostic" (2013)
- "The Deist" (2014)
- "Panteisten" (2015)
- "The Polytheist" (2016)
- "Monoteisten" (2017)
- "The Henotheist" (2018)
- "Animisten" (2019)
- "Shintoisten" (2020)