1. Quaderni dell'Istituto di Ricerca sulle Acque;Marchetti,1973
2. Quality Criteria for Water — 1976,1978
3. A. Arillo, C. Margiocco, F. Mclodia and P. Mensi, Chemosphere (in press).
4. Standard methods for the examination of water and wastewater;APHA,1975