The books, directories, and plaques series dates from 1931-1977 and is composed of books, directories, and plaques. The books are about aviation, navigation, photography, and art. One of the directories is an alumni directory for Thatcher School in Ojai, California, where Howard Hughes was a student from 1922-1923. The plaques were awarded to Hughes Productions by the Young Men’s Christian Association (YMCA) and the United Crusade.

The legal disputes series is largely composed of reference files of newspaper clippings dating from 1947-1976, as well as some legal documents. Over the course of Howard Hughes’ life he and his companies were involved in a large number of legal disputes, investigations, and hearings. This series contains material on Hughes appearance before the Senate Hearings of 1947, the political fight to build Dodger stadium in Chavez Ravine (Los Angeles, California) in the mid-1950s, the Oil Lease Probe of 1957, Hughes’ fight for control of TWA and Air West, and Clifford Irving and his publisher McGraw-Hill. A number of smaller legal disputes are also documented. Several of these involved trusted aides such as Noah Dietrich, John Meier, and Robert Mahue. However, it should be noted that legal disputes, investigations, and hearings related to RKO and HUAC are included in Series V.