Borja, A., Franco, J., P<U+00E9>rez, V., 2000. A Marine Biotic Index to Establish the Ecological Quality of Soft-Bottom Benthos Within European Estuarine and Coastal Environments. Mar. Pollut. Bull. 40, 1100<U+2013>1114. doi:10.1016/S0025-326X(00)00061-8
Rygg, B., 2013. Norwegian Sensitivity Index (NSI) for marine macroinvertebrates, and an update of Indicator Species Index (ISI). Norwegian Institute for Water Research
Rygg, B., 2002. Indicator species index for assessing benthic ecological quality in marine waters of Norway. Norwegian Institute for Water Research