i
Re: the request for references for articles on differential pricing,
see Hamaker's and Astle's mid-80s articles--1)Recent Pricing Patterns
in British Journal Publishin in Library Acquisitions:Theory and
Practice 8:229(1984) andPricing by Geography:  British Journal
Pricing 1986, including developments in other countrie in same
journal 10:170(1986).

Betsy Kruger, University of Illinois at Urbana-Champaign