Nautiyal. Shivanand. (2012). Paryavaran: Samasya aur samadhan. Samayik prakashan.
Dyfyniad Arddull ChicagoNautiyal. Shivanand. Paryavaran: Samasya Aur Samadhan. New Delhi: Samayik prakashan, 2012.
Dyfyniad MLANautiyal. Shivanand. Paryavaran: Samasya Aur Samadhan. Samayik prakashan, 2012.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.