APA (7th ed.) Citation

Gibbons, W., & McCarroll, D. (1993). Geology of the country around Aberdaron, including Bardsey Island : memoir for 1:50,000 geological sheet 133 (England and Wales) / W. Gibbons and D. McCarroll: Memoir for 1:50,000 geological sheet 133 (England and Wales). HMSO.

Chicago Style (17th ed.) Citation

Gibbons, Wes, and D. McCarroll. Geology of the Country Around Aberdaron, Including Bardsey Island : Memoir for 1:50,000 Geological Sheet 133 (England and Wales) / W. Gibbons and D. McCarroll: Memoir for 1:50,000 Geological Sheet 133 (England and Wales). London: HMSO, 1993.

MLA (9th ed.) Citation

Gibbons, Wes, and D. McCarroll. Geology of the Country Around Aberdaron, Including Bardsey Island : Memoir for 1:50,000 Geological Sheet 133 (England and Wales) / W. Gibbons and D. McCarroll: Memoir for 1:50,000 Geological Sheet 133 (England and Wales). HMSO, 1993.

Warning: These citations may not always be 100% accurate.