Format: in text citation
In this area a spring and earthworks are also shown (Map publisher, Year) …
Format: reference
Map publisher (Year) Map title. Sheet Number, Scale. Series. Place of publication: publisher.
Example: in text citation
In this area a spring and earthworks are also shown (Ordnance Survey, 1995) …
Example: reference
Ordnance Survey (1995) Kettering, Corby and the surrounding area. Sheet 141, 1:50 000. Landranger series. Southampton: Ordnance Survey.