Campion, J. (2017). Chris Williams, Police Control Systems in Britain 1775-1975. From parish constable to national computer, Manchester, Manchester University Press, 2014, 242 p., ISBN 978-0-7190-8429-4. URI:https://journals.openedition.org/chs.
শিকাগো স্টাইল (17 তম সংস্করণ) উদ্ধৃতিCampion, Jonas. "Chris Williams, Police Control Systems in Britain 1775-1975. From Parish Constable to National Computer, Manchester, Manchester University Press, 2014, 242 p., ISBN 978-0-7190-8429-4." URI:https://journals.openedition.org/chs 2017.
M.L.A (8 ম সংস্করণ) উদ্ধৃতিCampion, Jonas. "Chris Williams, Police Control Systems in Britain 1775-1975. From Parish Constable to National Computer, Manchester, Manchester University Press, 2014, 242 p., ISBN 978-0-7190-8429-4." URI:https://journals.openedition.org/chs, 2017.