1. Quality control in crowdsourcing systems: issues and directions;Allahbakhsh;IEEE Internet Comput.,2013
2. Bicheron, P., Defourny, P., Brockmann, C., Schouten, L., Vancutsem, C., Huc, M., Bontemps, S., Leroy, M., Achard, F., Herold, M., Ranera, F., Arino, O., 2008. Globcover: Products description and validation report.
3. Data validation in citizen science: a case study from Project FeederWatch;Bonter;Front. Ecol. Environ.,2012
4. Geographically weighted regression-modelling spatial non-stationarity;Brunsdon;J. R. Stat. Soc. Ser. Stat.,1998
5. Using control data to determine the reliability of volunteered geographic information about land cover;Comber;Int. J. Appl. Earth Obs. Geoinformation,2013