APA (7th ed.) Citation

Parkinson, D., Gray, T., & Williams, S. T. (1971). Methods for studying the ecology of soil micro-organisms. Blackwell.

Chicago Style (17th ed.) Citation

Parkinson, Dennis, T.R.G Gray, and S. T. Williams. Methods for Studying the Ecology of Soil Micro-organisms. Oxford [etc.]: Blackwell, 1971.

MLA (9th ed.) Citation

Parkinson, Dennis, et al. Methods for Studying the Ecology of Soil Micro-organisms. Blackwell, 1971.