Cita APA (7a ed.)

Jarvis, R. A., & Ashley, G. D. (1977). Soils of the Hexham district (Sheet 19). Soil Survey of England and Wales.

Cita Chicago Style (17a ed.)

Jarvis, R. A., y George Donald Ashley. Soils of the Hexham District (Sheet 19). Harpenden: Soil Survey of England and Wales, 1977.

Cita MLA (9a ed.)

Jarvis, R. A., y George Donald Ashley. Soils of the Hexham District (Sheet 19). Soil Survey of England and Wales, 1977.