| Title | Authors | Year | 
|---|---|---|
| Nitrate in soil water | 
                               Westling, O…  | 
                                                                                        1991 | 
| Effects of sulphur dioxide on the development of fungal diseases of winter barley in an open-air fumigation system. | 
                               Mansfield,…  | 
                                                                                        1991 | 
| Uptake, accumulation and translocation of arsenate in arsenate-tolerant and non-tolerant Holcus lanatus L. | Meharg, A. A… | 1991 | 
| Environmental Health Criteria 125 Platinum | 
                               WHO,  | 
                                                                                        1991 | 
| Physiological-effects of long-term exposure to low concentrations of SO2 and NH3 on poplar leaves | 
                               Hove, L.W.A…  | 
                                                                                        1991 | 
| Nitrogen Uptake and Allocation by Calluna-Vulgaris (L) Hull and Deschampsia-Flexuosa (L) Trin Exposed to 15NH3 | 
                               Dueck, T.A…  | 
                                                                                        1991 | 
| Effects of ionising radiation on aquatic organisms | 
                               National…  | 
                                                                                        1991 | 
| Acid deposition: its nature and impacts | 
                               Last, F.T…  | 
                                                                                        1991 | 
| Acidic deposition: its nature and impacts | 
                               Last, F.T…  | 
                                                                                        1991 | 
| The Distribution and Breeding Site Characteristics of Newts in Cumbria, England. | 
                               Denton, J.S…  | 
                                                                                        1991 |