1. Barker, P. G. (1993). Pictorial Communication. In D. Burger & J.-C. Sperandio (Eds.), Proceedings of the Conference on Non-Visual Presentations of Data in Human-Computer Interactions (Vol. 232, pp. 55-77). Paris: INSERM.
2. Barker, P. G. (2009). Pictures of the sea at Whitby. Retrieved April 26, 2010, from http://src-weblog.blogspot.com/2009/06/pictures-of-sea-at-whitby.html
3. Barker, P. G. (2010a). A-Walking: Weardale Wanderings (Pictures). Retrieved April 26, 2010, from http://www.philip-barker.info/Phil-B-50/ShowPics.html
4. Barker, P. G. (2010b). Enquiry-Based Learning Using Pictures: The Geograph Project. In Proceedings of the CBLIS-2010 International Conference, Warsaw, Poland.
5. Pictorial communication with computers