Dragnet 67 to Sierra
4 connections
Dragnet 67
Dragnet
Dragnet spun off Dragnet 67
Adam-12
The main characters from Adam-12 appear as witnesses in an episode of Dragnet
Emergency!
Emergency! had a crossover with Adam-12 to find a boy who ran away from the hospital.
Sierra
The fictional Sierra National Park of Sierra is in the same universe as Emergency!