?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adissertation&rft.aulast=Nunez&rft.aufirst=Iskra&rft.au=Nunez%2C+Iskra&rft.degree=Doctoral&rft.inst=Institute+of+Education%2C+University+of+London&rft.title=Critical+realist+activity+theory+(CRAT)&rft.tpages=323&rft.date=2012