Bradford's law

Suppose further that in order to find another dozen articles of interest, the researcher would have to go to an additional 10 journals.

Like Zipf's law, to which it is related, we do not have a good explanation for why it works, but knowing that it does is very useful for librarians.

What it means is that for each specialty, it is sufficient to identify the "core publications" for that field and only stock those; very rarely will researchers need to go outside that set.

Armed with this idea and inspired by Vannevar Bush's famous article As We May Think, Eugene Garfield at the Institute for Scientific Information in the 1960s developed a comprehensive index of how scientific thinking propagates.

The interpretation of Bradford's law in terms of a geometric progression was suggested by V. Yatsko,[6] who introduced an additional constant and demonstrated that Bradford distribution can be applied to a variety of objects, not only to distribution of articles or citations across journals.

V. Yatsko's interpretation (Y-interpretation) can be effectively used to compute threshold values in case it is necessary to distinguish subsets within a set of objects (successful/unsuccessful applicants, developed/underdeveloped regions, etc.