Doctor Who: The Three Doctors

From Author Wars - https://authorwars.com/publications/doctor-who-the-three-doctors-144181.html

Overview:

Title: Doctor Who: The Three Doctors
Author: Terrance Dicks
Year: 1979
ISBN-10: 0426115783
Publisher: Target / W. H. Allen
Price: £0.75
Pages: 127
Binding: Paperback
Type: Novel
Title Reference: The Three Doctors
Notes: Incorrectly titled "Doctor Who and The Three Doctors" on cover only.
Third impression.
Has Wyndham W on back cover.
Australia $2.75, Canada £1.95 (sic), New Zealand $2.60, Malta 80c.