15 books in series

Star Trek Adventures

Star Trek Adventures is a 15-book series with 15 released primary works first released in 1970 with contributions by James Blish, Sondra Marshak, Joe Haldeman, Kathleen Sky, Gordon Eklund, Stephen Goldin, Enric, Myrna Culbreath, Jack C. Haldeman II, and David Gerrold.

Spock Must Die!
Star Trek: The New Voyages
Verschwörung an Bord der Enterprise
Planet of Judgment
Star Trek: The New Voyages 2
Vulcan!
The Starless World
Trek To Madworld
World Without End
The Fate of the Phoenix
Devil World
Perry's Planet
The Galactic Whirlpool
DEATH'S ANGEL
Mudd's Angels