The Starburst IMF -- An Impossible Measurement?
  The starburst IMF is probably as much of theoretical interest and practical relevance as it is a subject of observational controversy. In this conference paper we review the most common methods (star counts, dynamical masses, and line ratios) to derive or constrain the IMF, and discuss potential problems and shortcomings that often lead to claims of anomalous IMF slopes and mass cut-offs. 
Bernhard R. Brandl & Morten Andersen