Mannix to Sierra
4 connections
Mannix
Diagnosis: Murder
Mannix returned to TV on an episode of Diagnosis Murder to solve an old unsolved case with the help of Dr Mark Sloan.
Matlock
Diagnosis Murder's Dr Mark Sloan was defended by Matlock when Sloan was accused of murder
Emergency!
Both feature the fictional Trans Global Airlines
Sierra
The fictional Sierra National Park of Sierra is in the same universe as Emergency!