Here are some of his most notable series and works:
Firefly Series:
* Firefly: The Official Novelisation (2003)
* Firefly: The Verse (2005)
* Firefly: Big Damn Heroes (2006)
* Firefly: The Shepherd's Tale (2008)
* Firefly: The Siege of Trencher's End (2008)
* Firefly: The Making of a Browncoat (2010)
* Firefly: The Complete Series (2010)
Star Trek: Deep Space Nine Series:
* Star Trek: Deep Space Nine: The War of the Prophets: The Fall of the Prophets (2007)
* Star Trek: Deep Space Nine: The War of the Prophets: The Ascent (2009)
* Star Trek: Deep Space Nine: The War of the Prophets: The Birth of the Prophets (2011)
Other Sci-Fi Series:
* The Warlord Series: A military sci-fi series set in a future where humanity has colonized the galaxy.
* The Hammer's Slammers Series: A gritty military sci-fi series featuring a band of mercenaries fighting in a brutal galactic war.
* The Legion of the Damned Series: A series focusing on a group of genetically engineered soldiers fighting for survival in a war-torn galaxy.
* The Steel Remains Series: A series set in a medieval world where magic and technology coexist.
* The Hell's Devils Series: A series about an elite unit of soldiers fighting in a futuristic war against a powerful enemy.
* The Sundown Trilogy: A three-book series set in a post-apocalyptic world.
* The Sinful and the Damned Series: A series focusing on a group of mercenaries fighting for their survival in a dangerous and unforgiving galaxy.
Standalone Novels:
* The Martian Chronicles: A novel based on the classic Ray Bradbury story.
* The Space Merchants: A novel based on the classic Frederik Pohl and C.M. Kornbluth story.
* The Man Who Sold the Moon: A novel based on the classic Robert Heinlein story.
Other Works:
* The Warlord: Volume 1 (1995)
* The Warlord: Volume 2 (1995)
* The Warlord: Volume 3 (1996)
* The Warlord: Volume 4 (1996)
* The Warlord: Volume 5 (1997)
* The Warlord: Volume 6 (1997)
* The Warlord: Volume 7 (1998)
* The Warlord: Volume 8 (1998)
* The Warlord: Volume 9 (1999)
* The Warlord: Volume 10 (1999)
* The Warlord: Volume 11 (2000)
* The Warlord: Volume 12 (2000)
* The Warlord: Volume 13 (2001)
* The Warlord: Volume 14 (2001)
* The Warlord: Volume 15 (2002)
* The Warlord: Volume 16 (2002)
* The Warlord: Volume 17 (2003)
* The Warlord: Volume 18 (2003)
* The Warlord: Volume 19 (2004)
* The Warlord: Volume 20 (2004)
* The Warlord: Volume 21 (2005)
* The Warlord: Volume 22 (2005)
* The Warlord: Volume 23 (2006)
* The Warlord: Volume 24 (2006)
* The Warlord: Volume 25 (2007)
* The Warlord: Volume 26 (2007)
* The Warlord: Volume 27 (2008)
* The Warlord: Volume 28 (2008)
* The Warlord: Volume 29 (2009)
* The Warlord: Volume 30 (2009)
* The Warlord: Volume 31 (2010)
* The Warlord: Volume 32 (2010)
* The Warlord: Volume 33 (2011)
* The Warlord: Volume 34 (2011)
* The Warlord: Volume 35 (2012)
* The Warlord: Volume 36 (2012)
* The Warlord: Volume 37 (2013)
* The Warlord: Volume 38 (2013)
* The Warlord: Volume 39 (2014)
* The Warlord: Volume 40 (2014)
* The Warlord: Volume 41 (2015)
* The Warlord: Volume 42 (2015)
* The Warlord: Volume 43 (2016)
* The Warlord: Volume 44 (2016)
* The Warlord: Volume 45 (2017)
* The Warlord: Volume 46 (2017)
* The Warlord: Volume 47 (2018)
* The Warlord: Volume 48 (2018)
* The Warlord: Volume 49 (2019)
* The Warlord: Volume 50 (2019)
* The Warlord: Volume 51 (2020)
* The Warlord: Volume 52 (2020)
* The Warlord: Volume 53 (2021)
* The Warlord: Volume 54 (2021)
* The Warlord: Volume 55 (2022)
* The Warlord: Volume 56 (2022)
Note: This is just a sample of his work. He has written over 100 books and numerous short stories. You can find a more extensive list of his publications on his website or on sites like Goodreads.