PF Chisholm is the pen name of Patricia Finney, so if you want the full story, you'll have to find Patricia Finney's Author Page. I used P F Chisholm as a pen name because when I started the Sir Robert Carey series all those years ago, I wanted to make a difference between my Patricia Finney books and the PF Chisholm books which were much more genre, being historical crime. However I now think that was probably not a very smart idea, because it's caused confusion and Chisholm isn't an easy name to spell! (You pronounce it "Chisum")
Anyway, the name was my paternal great-grandmother's maiden name and it was once a small riding surname, so that's another reason for using it.
Enjoy the Carey books, find my other books under Patricia Finney - and get at least two of your friends to buy them too.