| Title | Authors | Year |
|---|---|---|
| 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 |
| Nitrate in soil water |
Westling, O… |
1991 |
| Acid rain since 1985 - times are changing |
Brydges, T.… |
1991 |
| Effects of sulphur dioxide on the development of fungal diseases of winter barley in an open-air fumigation system. |
Mansfield,… |
1991 |
| Changes in species composition of semi-natural vegetation associated with the increase in atmospheric inputs of nitrogen |
Pitcairn, C… |
1991 |
| A Field-Study of Fertilization and Embryonic Development in the Common Frog (Rana-Temporaria) with Particular Reference to Acidity and Temperature |
Beattie, R.… |
1991 |
| Decline of ectomycorrhizal fungi in Europe. |
Arnolds, E… |
1991 |
| Environmental Health Criteria 125 Platinum |
WHO, |
1991 |
| Zeigerwerte von Pflanzen in Mitteleuropa |
Ellenberg,… |
1991 |