This is my main paper on the subject, which generalises a method proposed by Kochanek to `arbitrary' cosmological models and looks at the influence of selection effects. It is an extension of work I did in my Diplom (similar to master's) thesis here at the Hamburg Observatory and has appeared in Astronomy and Astrophysics (308, 2, 359).
The links below point to one file containing the complete text, all figures and tables etc.
As are most of my publications this is available in more than one form: