2 books found:
  Title Year Rating
Star Trek: The Original Series #35: The Romulan Way
by Diane Duane, Peter Morwood (Aug 1987)
Year: 2276 - Goodreads Rating: 3.91 (1,305)
Also: Rihannsu #2
The capture of a Starfleet officer by the Romulans forces an undercover Federation agent to make a fateful choice - between maintaining her cover and saving the life of Dr. Leonard McCoy.
3.91 (1,305)
Star Trek: The Original Series #48: Rules of Engagement
by Peter Morwood (Feb 1990)
Year: 2278 - Goodreads Rating: 3.54 (613)
A sudden revolution on the planet Dekkanar brings the Enterprise running to evacuate Federation personnel trapped there. Meanwhile, an experimental Klingon warship sets forth on a mission of its own, a warship with hidden capabilities, commanded by a warrior who will stop at nothing to bring glory to his Empire. The Klingon ship's destination? The planet Dekkanar.
3.54 (613)