APA (7th ed.) Citation

Butler, B. C., & Bell, J. D. (1988). Interpretation of geological maps. Longman u.a.

Chicago Style (17th ed.) Citation

Butler, B. C., and John D. Bell. Interpretation of Geological Maps. Harlow, Essex u.a: Longman u.a, 1988.

MLA (9th ed.) Citation

Butler, B. C., and John D. Bell. Interpretation of Geological Maps. Longman u.a, 1988.