Zero-count

Korner-Nievergelt, F., Strebel, N., Buckland, S.T., Freeman, R., Gregory, R.D., Guélat, J., Isaac, N.J., Rae, L.M., Roth, T., Schirmer, S., Soldaat, L.L., Voříšek, P. & Sattler, T. (2022) Multi-species population indices for sets of species including rare, disappearing or newly occurring species. Ecological Indicators, 140, 109005+.