337491document111637hager-et-al-2025-how-much-citizen-science-does-city-science-need.pdfapplication/pdff67516a4ae77cadcdf35faf120a6e1c5MD59670612025-11-11 17:36:46https://pure.iiasa.ac.at/id/eprint/20975/1/hager-et-al-2025-how-much-citizen-science-does-city-science-need.pdf