British Library. National Preservation Office. (1998). NPO journal. National Preservation Office, The British Library.
Cita Chicago Style (17a ed.)British Library. National Preservation Office. NPO Journal. London: National Preservation Office, The British Library, 1998.
Cita MLA (9a ed.)British Library. National Preservation Office. NPO Journal. National Preservation Office, The British Library, 1998.
Precaución: Estas citas no son 100% exactas.