SYMOENS, J.-J., DEVOS, P., RAMMELOO, J. & VERSTRAETEN, C. (Eds.) Biological Indicators of Global Change (PDF format)
SYMOENS, J.-J., DEVOS, P., RAMMELOO, J. & VERSTRAETEN, C. (Eds.) Biological Indicators of Global Change Symposium Brussels, 7-9 May 1992 (264 pp.: 63 fig., 24 tab., 1993)