APA (7th ed.) Citation

Oswald, A., Ainsworth, S., Pearson, T., & Frodsham, P. (2013). Hillforts: Prehistoric strongholds of Northumberland National Park (Version 1.0.). English Heritage.

Chicago Style (17th ed.) Citation

Oswald, Alastair, Stewart Ainsworth, Trevor Pearson, and Paul Frodsham. Hillforts: Prehistoric Strongholds of Northumberland National Park. Version 1.0. Swindon: English Heritage, 2013.

MLA (8th ed.) Citation

Oswald, Alastair, et al. Hillforts: Prehistoric Strongholds of Northumberland National Park. Version 1.0. English Heritage, 2013.