Question: Along with the author of the video game Eureka who co-founded the gamebooks "Fighting Fantasy"?

Context paragraphs:
Eureka! (video game): Eureka!  is a video game for the Commodore 64 and ZX Spectrum computers, written by Ian Livingstone, developed by Novotrade for Andromeda Software and published by Domark in 1984.

Titan (world): Titan is the fantasy world which serves as the setting for the majority of Steve Jackson and Ian Livingstone's "Fighting Fantasy" and "Sorcery! " gamebooks and novels.  The title contains "backstory on...the villains and NPC's" found throughout the "Fighting Fantasy" series.

Cretan Chronicles: Cretan Chronicles is a trilogy of single-player role-playing fantasy gamebooks written by John Butterfield, David Honigmann and Philip Parker, and illustrated by Dan Woods.  The Cretan Chronicles were published by Puffin between 1985 and 1986 under the Adventure Gamebooks banner, which also covered the more popular Fighting Fantasy and the related "Sorcery! " series, as well as the one-off Shakespearean-era role-playing game Maelstrom.

List of Fighting Fantasy gamebooks: "Fighting Fantasy" is a series of single-player fantasy roleplay gamebooks created by Steve Jackson and Ian Livingstone.  The first volume in the series was published by Puffin in 1982, with the rights to the franchise eventually being purchased by Wizard Books in 2002.  The series distinguished itself by featuring a fantasy role-playing element, with the caption on each cover claiming each title was "a Fighting Fantasy gamebook in which YOU are the hero!"  The popularity of the series led to the creation of merchandise such as action figures, board games, role-playing game systems, magazines, novels and video games.

Advanced Fighting Fantasy: Advanced Fighting Fantasy (AFF) is a British roleplaying game based on the "Fighting Fantasy" and "Sorcery! " gamebooks, and was published in 1989.  A second edition was published in 2011.  It takes place in the world of Titan.

The Warlock of Firetop Mountain: The Warlock of Firetop Mountain is a single-player adventure gamebook written by Steve Jackson and Ian Livingstone, and illustrated by Russ Nicholson.  Originally published by Puffin Books in 1982, the title is the first gamebook in the Fighting Fantasy series.  It was later republished by Wizard Books in 2002.  As well as launching the Fighting Fantasy series, the gamebook inspired two direct sequels and five novels, and was adapted into a board game and a video game.

Ian Livingstone: Ian Livingstone CBE (born 29 December 1949 ) is an English fantasy author and entrepreneur.  Along with Steve Jackson, he is the co-founder of a series of role-playing gamebooks, "Fighting Fantasy", and the author of many books within that series.  He is also one of the co-founders of prominent games company Games Workshop.

Jonathan Green (writer): Jonathan Green is a freelance writer.  He writes science fiction and fantasy novels for adults (Pax Britannia), adventure gamebooks for children (Fighting Fantasy), and non-fiction books for all ages.  He has written for various franchises, from "Sonic the Hedgehog" and "Doctor Who" ("The Horror of Howling Hill"), to books set within Games Workshop's "Warhammer" and "Warhammer 40,000" game universes.

Clash of the Princes: Clash of the Princes were two books ("The Warrior's Way" and "The Warlock's Way") released as a box set by Puffin Books in 1986, written by Andrew Chapman and Martin Allen and illustrated by John Blanche.  They could be played as standard Fighting Fantasy gamebooks or could be combined for a two-player experience.  In the two-player game, two scores (Action and Status) are kept track of on a piece of paper in order to keep both players' game experiences synchronized.

Carl Sargent: Carl L. Sargent (born December 11, 1952, in Caerleon, Monmouthshire, Wales) is a British parapsychologist and author of several roleplaying game-based products and novels, using the pen name Keith Martin to write Fighting Fantasy gamebooks.

Supporting paragraphs: Eureka! (video game) Ian Livingstone
Answer: Steve Jackson