I'm reading the book now - it is carefully and clearly written. I listened to an interview of Woodward by Stephen Colbert and Woodward described how "deep background" works - he most often is able to tape the interviews to be sure every quote is exact, but as noted above, he doesn't name his sources. I missed the Gross interview but just looked it up: Fresh Air, 9-11-2018.

This book sold out so quickly that Amazon that usually sends them on the day of release said I had to wait at least two weeks; I cancelled that order and got it on Kindle instead and am reading it on my Amazon Fire tablet. I prefer paper, but didn't want to wait.