Keller, H. M., Forster, F., & Weibel, P. (1986). Factors affecting stream water quality: results of a 15 year monitoring study in the Swiss prealps. In D. Lerner (Ed.), IAHS publication: Vol. 157. Monitoring to detect changes in water quality series. Proceedings of a symposium held during the 2nd scientific assembly of the international association of hydrological sciences at Budapest, Hungary, July 1986 (pp. 215-225). IAHS Press.