The evolution of the misprint distribution is described by the following rate equations (NK is the number of misprints that appeared K times; N is the total number of citations):
            
It’s stationary solution is:           with
Zipf law exponent:
The rate equation for the total number of misprints is:
The solution is:     Given that
we get:
Misprint propagation model
A typical outcome of a numerical simulation of the misprint propagation model   ( R=0.2 ) compared with the actual misprint data.
Each new citer finds the reference to the original in any of the papers that already cite it. With probability R he reads the original. With probability 1-R  he copies the citation from the paper he found the citation in. In any case, with probability M he introduces a new misprint.