Companion Books

I'm reading Rosemary Verey, The Life & Lessons of a Legendary Gardener by Barbara Paul Robinson.  It's a juicy bio for gardening sort of folks and maybe for folks who are not so inclined to pick up a shovel.


But now that I've reached the part in the book where Rosemary has decided to get her hands dirty, I decided to grab another book. Rosemary Verey's Making of a Garden is the perfect companion to her biography.  

Just curious--Have you ever read a book with a companion one?