Vidar Vambheim has updated the Required Readings for section ii) Approaches to Peace I: Negative Peace. Barash's readings should be:

Barash, David P. (ed.): Approaches to Peace (Oxford University Press, 2000), Ch. 2, (various authors): “Building Negative Peace”, pp. 61-121: (60 pp).

Find the updated syllabus here and at the SVF-3021 page: here