1. Brown L.R., in State of the World 1996, Ed by Brown L.R., Earthscan Publications Limited, London, p. 3 (1996).
2. Brown L.R., in State of the World 1997, Ed by Brown L.R., Earthscan Publications Limited, London, p. 23 (1997).
3. Gardner G., in State of the World 1996, Ed by Brown L.R., Earthscan Publications Limited, London, p. 78 (1996).
4. Brown L.R., in State of the World 1998, Ed by Brown L.R., W.W. Norton & Company, New York, p. 3 (1998).