APA
Ordnance Survey, . (1983). Proceedings of the Ordnance Survey digital mapping seminars held at Leeds University, 20 & 21 September 1983. Southampton: Ordnance Survey.
Chicago
Ordnance Survey, . 1983. Proceedings of the Ordnance Survey digital mapping seminars held at Leeds University, 20 & 21 September 1983. Southampton: Ordnance Survey.
Harvard
Ordnance Survey, . (1983). Proceedings of the Ordnance Survey digital mapping seminars held at Leeds University, 20 & 21 September 1983. Southampton: Ordnance Survey.
MLA
Ordnance Survey, . Proceedings of the Ordnance Survey digital mapping seminars held at Leeds University, 20 & 21 September 1983. Southampton: Ordnance Survey. 1983.
