T. Lindeberg and D. Fagerström, ``Scale-space with causal time direction'', Tech. Rep. ISRN KTH/NA/P--96/04--SE, Jan. 1996. Also in Proc. 4th European Conference on Computer Vision. (PDF)
Daniel Fagerström, Temporal Scale Spaces. International Journal of Computer Vision 64(2-3): 97-106 (2005) and Scale Space 2003: 340-355 (PDF)
Daniel Fagerström, Galilean Differential Geometry of Moving Images. ECCV (4) 2004: 494-506 (PDF)
Daniel Fagerström, Spatio-Temporal Scale-Spaces. SSVM 2007: 326-337 (PDF)
Daniel Fagerström, Spatio-Temporal Scale-Space Theory. Stockholm: KTH Royal Institute of Technology; 2011. Trita-CSC-A, 2011:11.