From the Radio Times:

5.30 Colour
Dr Who

starring Tom Baker
in
The Sontaran Experiment
A two-part story by
BOB BAKER and DAVE MARTIN
Part 1
Earth is uninhabited or is it?  While the Doctor solves a mystery Harry and Sarah walk into a trap.
Incidental music by DUDLEY SIMPSON
Script editor ROBERT HOLMES
Designer ROGER MURRAY-LEACH
Producer PHILIP HINCHCLIFFE
Director RODNEY BENNETT

From the Radio Times  (This is for the omnibus edition that repeated the show in a condensed version without episode breaks):

6.25 Dr Who
A complete adventure in one programme
starring
Tom Baker as Dr Who
written by BOB BAKER, DAVE MARTIN
Planet Earth, 30,000 years in the future, in uninhabited - or is it?  The Doctor and his companions solve the mystery but walk into a deadly trap.
Incidental music by DUDLEY SIMPSON
Producer PHILIP HINCHCLIFFE
Director RODNEY BENNETT (Repeat)