Nirmala, R., R. Navamathavan, S.-J. Park, and H. Kim. “Recent Progress on the Fabrication of Ultrafine Polyamide-6 Based Nanofibers Via Electrospinning: A Topical Review”. Nano-Micro Letters, vol. 6, no. 2, Aug. 2014, pp. 89-107, doi:10.1007/BF03353773.