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
Nitrate in soil water

Westling, O…

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

Pitcairn, C…

1991
Zeigerwerte von Pflanzen in Mitteleuropa

Ellenberg,…

1991
Nitrogen Uptake and Allocation by Calluna-Vulgaris (L) Hull and Deschampsia-Flexuosa (L) Trin Exposed to 15NH3

Dueck, T.A…

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

Hove, L.W.A…

1991
The Distribution and Breeding Site Characteristics of Newts in Cumbria, England.

Denton, J.S…

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

Maitland, P…

1991
Effects of sulphur dioxide on the development of fungal diseases of winter barley in an open-air fumigation system.

Mansfield,…

1991
Environmental Health Criteria 125 Platinum

WHO,

 		1991