1. Nielsen, A. 1968. “An Investigation on Promoted Iron Catalysts for the Synthesis of Ammonia”. In , 3rd, Vol. 8, Copenhagen: Jul. Gjellerups Forlag.
2. Nielsen, A. 1968. “An Investigation on Promoted Iron Catalysts for the Synthesis of Ammonia”. In , 3rd, Vol. 7, Copenhagen: Jul. Gjellerups Forlag.
3. Fourier peak-shape analyses of catalyst iron and cold-worked iron*1