Richard Osman books in order
5 books in the catalogue, about 37 hours of reading in all; the shortest takes 7 hours and the longest 8 hours.
2 series in the catalogue.
Thursday Murder Club
5 books
The Thursday Murder Club 7.0 h 
The Man Who Died Twice 7.4 h 
The Bullet That Missed 6.8 h 
The Last Devil to Die 7.3 h The Impossible Fortune length not known
We Solve Murders
2 books
We Solve Murders 8.5 h We Chase Shadows length not known