Who called it the 'Hahn problem'?

In chapter 2 of my book Monetary Theory and Policy (The MIT Press, 4^th ed., 2017), I called the problem of establishing a positive value for money the 'Hahn problem'. Hahn described this problem in “On Some Problems of Proving the existence of an equilibrium in a monetary economy,” published in The Theory of Interest Rates, F. H. Hahn and F. P. R. Brechling eds. London: Macmillan, 1965. Pp. 126- 135. In the 4th edition of Monetary Theory and Policy, the reference to the Hahn problem appears on p. 41, and I credited Truman Bewley with naming it in his paper “A difficulty with the optimum quantity of money”, Econometrica 1983, 51(5), 1485-1504. 

Recently, Pierrick Clerc of the HEC Liège School of Management (https://sites.google.com/site/pierrickclerc/) has pointed out to me that the term was used a decade earlier by Kevin Sontheimer in “The determination of money prices”, Journal of Money Credit and Banking, 1972, 4(3), 489-508. Sontheimer solves the Hahn problem by employing a model in which there are costs to transacting that take the form of foregone leisure. This means his model falls within the general class of shopping time models discussed in section 3.2.1 of chapter 3 of Monetary Theory and Policy.

I would like to thank Pierrick for sending me the Sontheimer paper.