Infinitely cern: memories of fifty years of research 1954-2004
Suzanne Hurter, 2004
 Buku Referensi
D’Onofrio, Mauro, editor
Fifty years of quasars : from early observations and ideas to future research
[Springer, ], 2012
 eBooks
Fifty years of Indian parliament
edited by G.C. Malhotra
Lok Sabha Secretariiat, 2002.
 Buku Teks SO
Hazeu, H.A.G.
Fifty years of electronic components 1921-1971
N.V. Philips Gloeilampenfabrieken, 1971
 Buku Teks
Scott-James, R.A.
Fifty years of English literature 1900-1950
Longman, 1951
 Buku Teks