1. Farming, fertilizers and the nitrate problem;Addiscott,1991
2. Nutrient contents in drained water from pipe drainage systems;Borin,1991
3. Nitrates removed by pipe drains in two cropping systems;Ceccon;Eur. J. Agron.,1993
4. Analysis of water balances;de Ridder,1994
5. Ricerche sul drenaggio tubolare sotterraneo e sulla sub-irrigazione nel Veneto (2 ° contributo);Giardini;Irrigazione,1983