Hello there, I have a few questions about CHAT. I have read a lot of Engestroms work which from my understanding is based on CHAT but revitalised as Expansive Learning Theory and or Third Generation Activity THeory and now Fourth Generation Activity. I am wondering how to reference in my phd. It gets murky to me ... I am using the triangle representation and a lot of Engestrom's (and his collegues) explanations. Who should I attribute the triangle model with the constructs - Rules, Community, Mediating Tool, Division of labour, the subject and object to? Hoping to find some clarity