Recommended reading - These Are the Voyages - TOS: Season Three, by Marc Cushman & Susan Osborn (2015):

These Are the Voyages - TOS: Season Three

By Marc Cushman & Susan Osborn.

Foreword by David Gerrold.

These Are The Voyages series.

Published by Jacobs Brown Press.

Published 2015.

Paperback.

ISBN-10: 0989238180

ISBN-13: 978-0989238182

Description:

Marc Cushman's biography of Star Trek the original series (TOS) takes you back in time for the final season of this iconic television show, to the production offices, the writers' room, onto the soundstages, and in front of your TV sets for what many thought would be Star Trek's final voyage. Included are hundreds of memos between Roddenberry, the producers and staff, production schedules, budgets, fan letters, behind-the-scene images, and the TV ratings. You'll find out the real reason Star Trek was cancelled. So buckle your seat belts, this final trek gets really bumpy.