Piret Peiker has published a chapter (co-authored with Peeter Sieg), entitled:

‘There Is More to Groups of People Than Just Groups and People: On Trans-Actional
Analysis and Nationalism Studies’ in John Dewey and the Notion of Transaction, A Sociological Reply on Rethinking Relations and Social Processes, ed Christian Morgner (Palgrave 2020), pp. 55-81 (Green access here).