A model for measuring the congestion in library shelves after j years (j∈ ℕ) is obtained by taking j-fold convolutions of
the distributions that describe the yearly growth of literature (e.g., periodicals, books on a certain topic,…) From this
one can estimate the expected number of critical points in the shelf, after j years. One can also calculate the probability
that there will be m (m∈ ℕ) critical points after j years.
The paper closes by examining two concrete cases.