Thomas L. Harper and Stanley M. Stein (1995), 'A Classical Liberal (Libertarian) Approach to Planning Theory', in Sue Hendler (ed.), Planning Ethics: A Reader in Planning Theory, Practice and Education, New Brunswick, NJ: Center for Urban Policy Research, pp. 11-29.

DOI link for Thomas L. Harper and Stanley M. Stein (1995), 'A Classical Liberal (Libertarian) Approach to Planning Theory', in Sue Hendler (ed.), Planning Ethics: A Reader in Planning Theory, Practice and Education, New Brunswick, NJ: Center for Urban Policy Research, pp. 11-29.

Thomas L. Harper and Stanley M. Stein (1995), 'A Classical Liberal (Libertarian) Approach to Planning Theory', in Sue Hendler (ed.), Planning Ethics: A Reader in Planning Theory, Practice and Education, New Brunswick, NJ: Center for Urban Policy Research, pp. 11-29.