Hansjoerg von BrevernKateryna SynytsyaSystemic-Structural Theory of Activity: A Model for Holistic Learning Technology Systems.745-7492005conf/icalt/2005ICALThttps://doi.org/10.1109/ICALT.2005.250https://doi.ieeecomputersociety.org/10.1109/ICALT.2005.250db/conf/icalt/icalt2005.html#BrevernS05