Παραπομπή APA

Smith, R. A., Alexander, R. B., & Schwarz, G. E. Natural background concentrations of nutrients in streams and rivers of the conterminous United States.

Παραπομπή Chicago Style

Smith, Richard A., Richard B. Alexander, και Gregory E. Schwarz. Natural Background Concentrations of Nutrients in Streams and Rivers of the Conterminous United States.

Παραπομπή MLA

Smith, Richard A., Richard B. Alexander, και Gregory E. Schwarz. Natural Background Concentrations of Nutrients in Streams and Rivers of the Conterminous United States.

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