1. I. Hoch, ‘Urban Scale and Environmental Quality’, in R. G. Ridker (ed.), Resource and Environmental Implications of U.S. Population Growth (Government Printing Office, Washington, 1972).
2. I. Hoch, ‘Income and City Size’, Urban Studies (1972).
3. R. F. Muth, Cities and Housing (Univ. of Chicago Press, 1969).
4. L. B. Lave and E. P. Seskin, ‘Air Pollution and Human Health’, Science, (1970), pp. 723–32.
5. R. Spirtas and H. J. Levin, Characteristics of Particulate Patterns 1957–1966 (National Air Pollution Control Admin., Pub. AP-61, 1970), p. 13.