Q about citing e-books and using certain sources

[Denny Zartman]

Two questions for the authors on this forum. Apologies for my ignorance.

One, do you ever cite e-books as sources in your books, and if so, how do you approach specifying locations in the e-book for your cite, as you would do for page numbers in a printed source?

Two, specifically about "The Kennedy Assassination Tapes" book by Max Holland. I was able to figure out on my own that Holland was a questionable writer from the way he tries to use his commentary to tell the reader not to always believe what they're reading. It's understandable why he would do that as the LN he is, because in my opinion there are more than a few conversations transcribed in his book that indicate suspicious happenings. So, theoretically, would you cite Holland's book as a source if you wanted to quote from the transcribed conversations, or would you use, and cite, a different source for the same content?