Here are the c-d authors.
Grant Callin - Saturn Alia
John W. Campbell - The Ultimate Weapon
Orson Scott Card - Ender's Game
Jayce Carr - Leviathon's Deep
Terry Carr - Fellowship of the Stars
Lin Carter - Time War
Jeffrey Carver - The Infinity Link
Jack Chalker - Twilight At The Well Of Souls
A. Bertram Chandler - Star Loot
C.J. Cherryh - Hunter of Worlds, Serpent's Reach, Book of Morgaine,Cuckoo's Egg, heck ALL of them except the short stories
John Christopher - Tripods trilogy
Arthur C. Clark - Rendevous With Rama
Jo Clayton - Drinker of Souls
Hal Clement - Through the Eye of a Needle
William Cochrane - Class Six Climb
Allan Cole & Chris Bunch - Sten series
Michael Coney - The Jaws That Bite, The Claws That Catch
Gerard Conway - Mindship
Glen Cook - The Black Company
Paul Cook - Halo
Edmund Cooper - A Far Sunset
Lee Correy - A Matter of Metalaw
Juanita Coulson - The Singing Stones
Robert Coulson - Gates of the Universe
Richard Cowper - Time Out of Mind
Joan Cox - Star Web
Ray Cummings - The Exile of Time
Damiel Da Cruz - The Ayes of Texas
Brian Daley - Jinx On a Terran Inheritance
John Dalmas - The Reality Matrix
Arsen Darnay - The Splendid Freedom
Avram Davidson - Clash of Star Kings
L. Sprague DeCamp - Lest Darkness Fall
Michael DeLarrabeiti - The Borribles
Lester DelRay - Police Your Planet
Ansen Dibell - Pursuit of the Screamer
Phillip Dick - Galactic Pot-Healer
Gordon Dickson - all of them
David Drake - all of them