1. Analytical Methods Manual. Inland Water Directorate. Water Quality Branch Ottawa Canada (Nitrogen Ammonia), 1981.
2. : Standard Methods, 13th Ed. 132: Nitrogen Ammonia, 1971, 222.
3. : Standards Part 3, Water, 1981, 275–284.
4. : Repertoire de Chimie Pure et Appliquée. 1859, 284.
5. Comecon (RGW): Standard Methods of Water Analysis (KGST Egységes vizvizsgálati módszerek) (In Hungarian). VITUKI, 1975, 97.