This primary source comes from the Collection RR-WHPO: White House Photographic Collection.
Full Citation: C44071-15A; Photograph of President Reagan and General Secretary Gorbachev signing the INF Treaty in the East Room of the White House; 12/8/1987; Reagan White House Photographs, January 20, 1981–January 20, 1989; Collection RR-WHPO: White House Photographic Collection; Ronald Reagan Library, Simi Valley, CA. [Online Version, https://www.docsteach.org/documents/document/photograph-of-president-reagan-and-general-secretary-gorbachev-signing-the-inf-treaty-in-the-east-room-of-the-white-house, March 28, 2024]