THE distribution of scientific articles in journals is known to conform closely to Bradford's law. If the journals are divided into groups, each containing the same number of articles on a given subject, then the number of journals in the succeeding groups form a geometrical progression1. The conditions for strict conformity with the law are that the bibliography be complete and of limited time span, and that it refers to a well defined subject. The law, however, seems to hold even when the conditions are not fully satisfied. An interesting discussion of the law and its application in library systems is given by Brookes2. No simple model of the mechanism responsible for the law exists2.