Contains annual files, assessments, bibliographies, planners, letters, conferences and symposium papers, and the unpublished writings of Gillum. Most of the material concerns Gillum's professional responsibilities as Ancient Studies Librarian at Brigham Young University, dating from 1970-2014.

Contains bibliographies, articles, event programs, indexes, and notes concerning Hugh Nibley and the presentation of Gillum's research on Nibley. Correspondence and articles written by Hugh Nibley are also included. The papers date from 1926 to 2009.

Contains memorandums, notes, and letters from Brigham Young University (BYU) faculty, as well as non-BYU correspondence with family, professional colleagues, editors, and Church authorities. The series dates from 1973 to 2015.