Cita APA

Gurcharan Singh. (2000). Pollution to purity of environment.

Chicago Edition Citation

Gurcharan Singh. Pollution to Purity of Environment. New Delh, Deep & Deep Publications, 2000.

Cita MLA

Gurcharan Singh. Pollution to Purity of Environment. 2000.

Atenció: Aquestes cites poden no estar 100% correctes.