Subject Count
X-15 aircraft 2
X-15 (Rocket aircraft) 8
X-15 (Rocket aircraft) -- History 3
X-15 (Rocket aircraft) -- History -- Congresses 2
"X", 1865-1924
X, 1929- 2
X, 1929- -- Trials, litigation, etc 2
X, 1934-1979 2
X, 1934-1979 -- Trials, litigation, etc 2
X, 1963-1992 -- Trials, litigation, etc 1
X, 1977- 1
X, 1977- -- Trials, litigation, etc 1
X-20 (Space glider) 1
X-22 (VTOL airplane) 1
X-29 aircraft 5
X-30 vehicle 1
X-31 aircraft 1
X-31 (Jet fighter plane) 3
X-32 (Jet fighter plane) 3
X-33 reusable launch vehicle 6
X-35 (Jet fighter plane) -- Maintenance and repair 1
X-37 vehicle 1
X-38 crew return vehicle 3
X-43A (Hypersonic plane) 1
X-43A (Hypersonic plane) [proposed] 1
X. B. W. (Xsiąże Biskup Warmiński), 1735-1801
X-Band 1
X-Bar-Syntax 4
X, Betty
X, Cassius, 1942-
Use instead:
X, Cassius, 1942-2016
X Chromosome 2
X chromosome 10
X chromosome -- Abnormalities 1
X chromosome -- Abnormalities -- Congresses 1
X Chromosome -- genetics 1
X Chromosome Inactivation 1
X Chromosome Inactivation -- physiology 3
X Club (London, England) 2
X-Club (University of Chicago) 1
X, Doctor 1
X-Effizienz 1
X. F. (Xavier Forneret), 1809-1884
X-files <Fernsehsendung> 1
X-Files (Motion picture) 1
X-files (Television program) 11
X-files (Television program) -- Criticism, interpretation, etc 1
X-files (Television program) -- History and criticism 1
X-files (Television program) -- Miscellanea 1
"X", Flying Officer, 1905-1974
X for I (M) 1
X-Ineffizienz 1
X-linked mental retardation 6
X-linked mental retardation -- Atlases 2
X, Louis
Use instead:
X, Madame, 1954-2005
Use instead:
X, Malcolm 1925-1965 1
X, Malcolm, 1925-1965 113
X, Malcolm, 1925-1965 -- Assassination 3
X, Malcolm, 1925-1965. Autobiography of Malcolm X 4