Professor Elizabeth Price Foley provided testimony to the United States Congress Committee on Science, Space & Technology. Her testimony addressed enforcing congressional subpoenas and can be viewed here. Professor Elizabeth Price Foley also participated in the question and answer session following the Committee hearing.
Below please find the link to view the the hearing. Professor Elizabeth Price Foley testimony begins at: 55:35.
https://science.house.gov/legislation/hearings/full-committee-hearing-affirming-congress-constitutional-oversight