Professor Daniel Castelo 
Pneumatology: A Guide for the Perplexed [EPUB ebook] 

This guide aims to elaborate and constructively engage some of the ongoing dogmatic challenges within the field of Christian pneumatology. Rather than a strict survey, the book largely represents a collection of working proposals on a number of relevant themes, including cosmology, mediation, the nature and role of Spirit-baptism, and discernment.
For those who have found pneumatology frustrating and confusing, the book can serve as an aid to clarify some of the most crucial matters at stake in the doctrine of the Holy Spirit and in turn provide some ways forward amidst the morass of possibilities available.