The House committee noted that it interviewed 73 individuals, resulting in 55 transcribed interviews.
The report also indicated that seven witnesses had invoked their Fifth Amendment protections against self-incrimination.
theepochtimes.com/why-are-the-br…
They come from closed hearings with former CIA Director John Brennan, former FBI Director James Comey, and former NSA Director Mike Rogers.
Interviews w/Dana Rohrabacher & Debbie Wasserman Schultz that are "being withheld as a “professional courtesy” extended to members of Congress who participated in the interviews with the understanding they would be confidential."
mercurynews.com/2018/09/28/hou…
It also notes "7 witnesses who have invoked their 5thAmendment protections" but, unfortunately gives no names.
republicans-intelligence.house.gov/uploadedfiles/…
I've written about these separate transcripts in depth.
The ones that @RichardGrenell refers to are new to us.