E.H. Schein, Addison-Wesley, 1999. This book emphasises the process of consultation, as the interaction between the client and the consultant is much more important than what is actually done. Its focus is primarily on the ‘how’, i.e. the processes that take place when one person advises another. It stresses the importance of the ‘psychological contract’ between the consultant and the client, and sets out basic principles underlying communication and feedback.