There are 2 books by P. O'Brien on BookOrb. A strong starting point is Debate aborted 1789-91 (1996). The bibliography below is in publication order, with series grouped in reading order.
Standalone books
Frequently asked questions
How many books has P. O'Brien written?
BookOrb lists 2 books by P. O'Brien.
Where should I start with P. O'Brien?
A good starting point is Debate aborted 1789-91 (1996).
What is the P. O'Brien books in order list?
In publication order: 1. Warrington Academy, 1757-86 (1989), 2. Debate aborted 1789-91 (1996).