Vain, A., Kaasalainen, S., Hyyppä, J. and Ahokas, E. 2012. Calibration of laser scanning intensity data using brightness targets. Geodesy and Cartography. 35, 3 (Aug. 2012), 77-81. DOI:https://doi.org/10.3846/1392-1541.2009.35.77-81.