Nielsen, A. (1968). An investigation on promoted iron catalysts for the synthesis of ammonia (3rd ed.). Gjellerup.
Lua i Stíl Chicago (17ú heag.)Nielsen, Anders. An Investigation on Promoted Iron Catalysts for the Synthesis of Ammonia. 3rd ed. Kobenhavn: Gjellerup, 1968.
Lua MLA (8ú heag.)Nielsen, Anders. An Investigation on Promoted Iron Catalysts for the Synthesis of Ammonia. 3rd ed. Gjellerup, 1968.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.