Title Authors Year
A Field-Study of Fertilization and Embryonic Development in the Common Frog (Rana-Temporaria) with Particular Reference to Acidity and Temperature

Beattie, R.…

1991
Changes in species composition of semi-natural vegetation associated with the increase in atmospheric inputs of nitrogen

Pitcairn, C…

1991
Environmental Health Criteria 125 Platinum

WHO,

 		1991
Zeigerwerte von Pflanzen in Mitteleuropa

Ellenberg,…

1991
Influence of HN3 and (HN4)2 SO4 on heathland vegetation

Van der…

1991
Effects of ionising radiation on aquatic organisms

National…

1991
Forestry and soil protection in the UK

Moffatt, A.…

1991
Increases in soil acidity in north west Wales between 1957 and 1990

…

1991
Physiological effects of long term exposure to low concentrations of SO2 and NH3 on poplar leaves.

Hove, L.W.A…

1991
Conservation of freshwater fish in the British Isles: the current status and biology of threatened species. Aquatic Conservation

Maitland, P…

1991