1. M. Appl (Ed.), in: Ullmann’s Encyclopedia of Industrial Chemistry, 6th Edition, 2000 electronic release, Wiely, Weinheim, 2000.
2. A. Nielsen, An Investigation on Promoted Iron Catalysts for Ammonia Synthesis, Jul. Gjellerups Forlag, Copenhagen, 1968.
3. A. Ozaki, K. Aika, in: J.R. Anderson, M. Boudart (Eds.), Catalysis: Science and Technology, Springer, Berlin, 1981.
4. S.R. Tennison, in: J.R. Jennings (Ed.), Catalytic Ammonia Synthesis, Plenum Press, New York, 1991.
5. Surface, catalytic and magnetic properties of small iron particles III. Nitrogen induced surface reconstruction