The Armchair Detective Series One
(& Prequel)
Series Collections
The Armchair Detective Series Two
The Armchair Detective Series Three
Special Editions
The Armchair Detective Series Four

The Back Cover descriptions in full:
The Armchair Detective Series Five
The Armchair Detective Special
The Armchair Detective Series Six Memory
The Armchair Detective Series Seven
The Armchair Detective Series Eight
The Fellowship
The Armchair Detective Series Nine
The Armchair Detective Special
The Armchair Detective Series Ten
Finding Eleanor The Final Series