Looks like filenames of the depositions that were just released.
Here are links to some of those:
Deposition of Ambassador William B. Taylor on October 22, 2019
http://docs.house.gov/meetings/IG/IG00/CPRT-116-IG00-D008.pdf
Deposition of Dr. Fiona Hill on October 14, 2019
http://docs.house.gov/meetings/IG/IG00/CPRT-116-IG00-D010.pdf
Interview Transcript of John Carlin (July 27, 2017)
http://docs.house.gov/meetings/IG/IG00/CPRT-116-IG00-D033.pdf
Interview Transcript of James Clapper (July 17, 2017)
http://docs.house.gov/meetings/IG/IG00/CPRT-116-IG00-D035.pdf
Interview Transcript of Dan Coats (June 22, 2017)
http://docs.house.gov/meetings/IG/IG00/CPRT-116-IG00-D037.pdf