Yrjo has papers where he speaks of cycles and networks of activities
but I am not sure which are in print. There is a website for the
Developmental Work Research Group in Helsinki which is not at my
fingertips, but which contain some materials.
The issue of time and triangularity and context and and are taken
up in my monograph on Cultural Psychology. But a good deal can
be found in the writings of various other xmca participants as well.
mike